natural sciences of philadelphia.

NATURAL SCIENCES OF PHILADELPHIA. 175

Descriptions of

new

_Organic

Remains from

the_Tertiary, Cretaceous

and

Jurassic

Rocks

ofNebraska.

BY

F. B.

MEEK AND

F. V.

HAYDEN.

The

_following

new

_{species of}fossil raollusca, belong mainly^tothe collections brought from

Nebraska

_bythe expeditionsunderthe

command

of Lieut.G. K.

Warren,^{of the U.S.}Top. Engrs.^{in 185(3-7}

and

8.

More

extended descriptions of these

and

theother speciesalready describedby^usfromthat region,together with remarks, comparisons,

and

full illustrations, will appear ^{in Lieut.}

War-

ren's final report.

TERTIARY SPECIES.

GASTEROPODA.

Helix _Evansi, A.

k

H. Shell small, suborbicular, spire depressed; volu- tions four

and

a halfto five, obliquely compressed,^or alittleconvexabove,

rounded

ontheouter_side,

and

_veryconvex below,^the

most

_{prominentpart}being nearthe umbilicus,concave_within,

and

each embracing on^theupper^sideabout half,

and

below_{nearly the} whole breadthofeverysucceeding^innerturn; sur- face

unknown

; umbilicus rather small, oraboutequalling the breadthofthe widestpart of the outer volution^; aperture nearlyobovate,^its longer diameter being^directed

outward and

_{upward. Height,}

(MO

inch; breadth, 17 inch.

Named

in

honor

of Dr.

John

_Evans, Geologist, ofOregon.

Locality

and

_position. Estuary beds^atthe

mouth

ofJudithRiver.

PLANORBrs vetulus,

M. &

H. Shell discoidal,

much

compressed,spireslight- ly concave, umbilicus shallow,very ^little broaderthantheconcavity

on

the upperside,

and

rather

more

thanone-third wider thanthe outerwhorl,

show-

ingabouthalf ofeachinner turn;volutions three

and

ahalf_{to four,}compress- edconvex above

and

below,^theupper^sidebeing^alittle

more

convex thanthe other, andsloping slightly

outward

from nearthe innermargin,rather distinct- lyangular around^theouterside, alittlebelowthe middle,

and

deeply concave withinforthe reception ofeach succeeding ^innerwhorl; sutures well defined,

though

^notvery deep; aperture sub-cordate, approaching anirregular hastate outline, very slightly oblique, having ^its longer ^{axis in} the direction of the greatestbreadthoftheshell; surfaceapparentlynearly smooth,or only

show-

ing obscure

marks

ofgrowth. Greatest breadth 23 inch

; height

005

inch.

Locality

and

_position.

Upper

part of the Tertiaryforming^the

Bad Lands

of

White

River.

Planorbis _Leidyi, M.

k

H. Shell small, 3ubdiscoidal; spireflat, or alittle

concave; volutions scarcely three, increasing rather rapidlyⁱⁿsize,not

embrac-

ingontheupperside,innerones almost_entirelyhidden

by

^thelastturn below,

allconvex above, rather narrowly rounded on^the upper outerside,ventricose

and rounded below

; suturewilldefined; umbilicus_{small, or}lessthanhalfthe breadth ofthe outer whorl,deep

and

_{scarcelypermitting}the inner volutionsto be counted; ^surface

marked by

^{fine delicatelinesof}

growth

; aperture sub- circular,or obliquely a^littleoval, flattened or

somewhat

concaveonthe inner side. Greatest breadth, 0-22 inch; height, 0-09 inch.

Named

in honorof Prof. Jos. Leidyof Philadelphia.

Locality

and

_position,

same

as^{la^t.}

CONCHIFERA.

Sph^riom

_{planum, M.}

&

H. Shell rather small,broadoval or subcircular,

much

_compressed;extremities

more

orlessregularlyrounded,the posterior

mar-

ginbeing sometimes faintlysubtruncate; base semi-oval in outline; cardinal margin rounding gradually from near^themiddle;beaksvery small,compressed,

and

_{scarcelyextending}

beyond

^thehinge margin,nearly central; surface

marked

I860.]

176 PROCEEDINGS OF THE ACADEMY OP

by

^fineirregular,obscure, concentric striae. Length, ^{0-38 inch}; height, 0-32 inch; convexity^{0.08 inch.}

Locality

and

_position.

Near

the

mouth

of

Grand

Riveronthe

Upper

^Missouri.

Sph^rium

recticardinale, M.

&

H. Shell of

medium

_size, transversely subelliptical, rathercompressed, verythin; anterior siderounded; base form- inga regularseraiellipticcurve; posteriorextremityobliquelysubtruncate_above,

and

rathernarrowly

rounded

below; cardinalmargin long andstraight; beaks verysmall,compressed,

and

_projectingbut _slightly above the hinge, located nearly half

way

^{between themiddle}

^and

the anteriorend

; surface

marked by

moderatelydistinct, irregular^linesofgrowth. Length,^{0-55 inch};height, 0*36 inch;breadth, 0-24 inch.

Locality andposition,

same

aslast.

Cyrena

(Corbicdla?) cytheriformis, M.

&

H. -Shellbroadtrigonal ovate,vary- ing^to subcircular, ratner thick

and

_strong; extremities

more

orless

rounded;

base semiovate, usually

more

_prominentbeforethan behindthemiddle; dorsal outline sloping from the beaks, the anterior slopebeing

more

abrupt than^the other,

and

_slightlyconcave, while ^the posterior ^is convex; beaks ratherele- vated, moderately gibbous,^locatedin advanceof themiddle; surface

marked by

^{fine linesof}growth,

which

sometimes

show

averyslighttendency^togather intosmall irregular concentric wrinkles. Length, ^inches;height, inch_; thickness, inch.

Locality

and

_{positio?i. Estuarybeds,}near

mouth

ofJudithRiver.

CRETACEOUS SPECIES.

CEPHALOPODA.

Genus

Phylloteuthis, M.

&

H.

Phylloteuthis subovatds, M.^{&. H.}

The

specimens on

which we

propose ^to found ^this genus

and

_species consist of the

expanded

portion of thepen ^or gladius. This organ

seems

tohave been corneous,

and

is thin, very

wide

or subovateⁱⁿform, a^littleconcaveonthe under_side,

and

convex above.

From

behindthemiddle ^itnarrows towards the_front,the outline of thelateral

mar-

ginsbeing convex, whilethe posteriorend is

more

or less obtuselyangular.

The

shaft is broken

away

ⁱⁿ our specimens, butthat portion of^itextending

backward and

forming^themidrib ofthe

expanded

part, ^is narrow, prominent,

and

rathersharply^carinateabove, while on^theunderside it is merelyrepre- sented

by

^a

narrow

_groove.

The

lateral expansions ^are crossed a little ob- liquely

backward and

outward, ^at an angle^of about 65 from the midrib,

by numerous

slender, ridgedparallelstriae,

which

are verynearlystraight,orvery slightlycurved

backward

neartheoutermargins.

Length

^of

expanded

part, exclusive of theshaft,1-55 inch; breadthof_do.,0-82 inch.

Apparently nearthe Liassicgenera Beloteuthis

and

Teudopsis, or at

any

^rate

tospecies thathave_been, with doubtful_propriety,rangedⁱⁿthese groups.

Localityandposition.

Moreau

_River, information No. 5.

Helicoceras

angulatum Of

this shell

we

haveseenbut a_singlenonseptate fragment, 2-78 inches inlength,witha diameterof 1-50 inches at the larger end,

and

1-37 inchesatthe smaller. It isrounded,or subcylindrical,

and makes

a broad(sinistral?) spiral curve,ⁱⁿsucha

manner

thatifcontinued around, ^the volutions

would

be disconnested,

and

encircle an umbilical _cavityapparently

more

than three times their

own

breadth.

The

surface is

ornamented

_bydis- tinctangular^costae,

which

_pass

around

thewhorls _obliquely

and

_support

two rows

ofnodes onthelowerouter_side,

where

they sometimes^bifurcate. Septa

unknown.

Localityandposition.

Head

ofsouth branch of

Shyenne

River, ⁱⁿ theupper part offormationNo. _4, of the

Nebraska

series.

[May,

NATURAL SCIENCES OF PHILADELPHIA. 177

Ammonites

placenta,^var.intercalaris. It ispossible this^shell

may

^bespe- cificallydistinctfrom A.placenta ofDekay, but ^it agreeswith that species so nearly that

we

are in doubt aboutthe propriety ofconsidering^itentitled to rank as a species. ^{It differs} externallyfrom the typical forms of Dekay's species, inbeing^ratherless compressed,

and

in having^aslightlylargerumbili- cus, whileinsteadof a single ^seriesof scarcely perceptible transversely elon- gated prominences on each _side,it has a

row

_{of small,}butdistinctnodesa littlelessthanone-third of the

way

^{acrossfromthe}dorsum,

and

another

more

prominent^seriesnearthe umbilicus. Italsodiffers in having^a

row

_{of small,} pinched, alternatingnodes on each of the

two

dorsal angles.

With

these external differences,however,^the septa of the shell under con- sideration, are sovery^{similarin alltheirdetails to those of}A.placenta, that

we

are at present inclined^toregard^itas a variety of that species.

It isalso

worthy

of note, that the formbeforeusisclosely related^toA._syr~

talisofMorton, being^{in fact}almostexactly intermediatebetweenthatshell

and

A.placenta, as wellⁱⁿform

and

externalornaments,^asinthe characters ofits septa. ^Its exact relations to these species can perhaps only^{be settled}

by

^a carefulcomparison^{of a}

more

extensiveseriesofspecimens than has _yet been obtained; inthe

mean

timeit

may

^be

made known

as a subspecies,under the

name

A._placenta, var. intercalaris,

and

shoulditprove distinct, ^it

may

^{take the}

latteras a_specificname. Itseemstoattainalarge^size.

Our

_specimen,

which

consists of inner septate whorls, ^is 5-70inchesinitsgreatest diameter,with athickness orconvexity^{of1-62inches.}

Locality

and

_position.

Sheyenne

River,ⁱⁿ theupperpart of Formation No. 4 of theNebraska Cretaceous series.

Ammonites

Vermilionensis, M.

&

H. Shell compressed ^discoidal; umbilicus large, veryshallow,

and showing

^aboutfour-fifths ofeach inner whorl; volu- tionsfiveormore,^rathersharply^carinatedaroundthe middleofthe dorsum,

and ornamented

on each side by nearly straight,simple,moderatelystrong, obtuse costae,

which show

a tendency ^to develope nodes^at each _extremity.

Greatest diameter 1-05inches; convexity about^{0-29 inch.}

Locality

and

_position.

Mouth

Vermilion _River, in Formation No. _2, of the Nebraska ^section.

Scaphites

Warreni,

^M.

&

H. Shell small, transversely subovate,moderately compressed,

rounded

onthe

dorsum

; umbilicusrather small; volutions sub- cylindrical, height

and

breadth nearly equal, increasing gradually^{in size};non- septate portion of ^last turn slightlycompressedlaterally,

and

deflected from the regularcurveof the others, so as ^to

become

nearly or quite disconnected atthe aperture. Surfaceof theinner whorls

ornamented by numerous

^small

costae,

which

increase _chiefly

by

implantation,andall cross the

dorsum

_very regularlywithout arching; on ^{the sidesof the} non-septate ^outer chamber, about every^{fourth or fifth} one of the costae is

much more

prominent and sharper thanthe others,

and

extends _quite across to the umbilical_side,while those betweendie_out,or coalesce withthe others at various distances.

Length ^1-45inches; height about^{1-22 inches}; breadth

057

inch.

Localityand_position.

Near

the Black _{Hills, in} formation No. 2 of the Ne- braskaSection.

Scaphites nodosus,^var.plends.

We

suspect ^the noblespecimen

we

here propose^tonotice provisionally, as a variety of Dr.Owen'sScaphites nodosus,

may

prove^tobelongto a distinct species,but as

we

are not yetfully satisfiedon this point,^itisperhaps^betterto regardit,forthe present, asa

marked

_variety of Dr. Owen's_species;

and

shouldfurther comparison demonstrate ^{that it is} entitled torank asa species,^itcan takeas aspecific

name

that

by which we

have designated^itasa_variety. ItdiffersexternallyfromDr.

Owen's

_{figure of}

S.nodosus,ⁱⁿbeing greatly

more

ventricose,

and

snorter in proportion ^{to its} height,whileitsinner

rows

ofnodesare

much

smaller

and

nearer the umbili-

I860.] 11

178 PROCEEDINGS OP THE ACADEMY OF

cus. There are also

some

differencesinthedetailsofthe septa,

which cannot

however, bereadilyexplained withoutfigures. ^{It is}likewise

much

_largerthan thespecimen represented

by

^Dr.

Owen,

^or

any

individualsof thatform

we

have seen, ^its length being 4-57 inches

; height ^3-87 inches,

and

its breadth2*53 inches.

Locality

and

_position.

On

Yellow Stone _River, 150milesabovethemouth,ⁱⁿ theupperpart offormationNo. 4of the

Nebraska

Cretaceous Series.

GASTEROPODA.

Aporrhais

_{paeva, M.}

&

H. Shell small, conical,subfusiform

; spire

moder-

ately elevated,

and

acute at the apex^{; volutions six}or seven,separatedby^a smallbutrather distinct suture,

and

_having

around

the middle _{a single}series ofveryoblique, flexuous folds, or node-like _costse,

which

donotextendtothe suture either

above

orbelow; lastwhorl havingjustbelowthe

row

of nodes, a small but well defined revolving angle; surface

marked by

very obscure linesofgrowth,

and

_{fine,closely set,revolving}striae. Length about^{0-28 inch;} breadth of

body

whorl, 0-15 inch^;apical angle a^littleconvex, divergence

33.

Localityand_position,

same

aslast.

Aporrhais

_sublevis,M.

&

H. Shellconical, orsubfusiform; spire elevated;

volutions seven or more, convex,

and

_separated

by

^{a rather} distinct,though not deep^suture;lastoneconvex_above,

and

_abruptlycontractedbelow,having a (single?)small,revolving angle,

which

_passes aroundtothe suture,but is

not seen on the succeeding ^{turn above.} Surface _polished,

and marked by

moderatelydistinct,arcuate lines of growth,

which

are crossed

by

^{rather ob-} scure revolving ^lines, nearlyequalling the spaces between, on ^the spire, but

more

_distant,with sometimes a few indistinct, irregular,very fine, parallel striae

between

onthe

body

^whorl; aperture

and

_lip

unknown.

Length about 0-54 inch; breadth of

body

whorl,^0-26 inch; apical angle slightly convex, divergence

37.

Locality

and

_position. Yellow Stone _River,

Upper

part of No._4,

Nebraska

section.

Dentaliom

pacperculum,

M. &

H. Shell small, arcuate, slender

and

_taper- ing gradually^{; section circular}; substance comparatively ^thick; surface smooth, but

showing

^undera magnifierextremelyfine,obscurelines ofgrowth,

which

_passaround

somewhat

_{obliquely. Length(of}an incomplete specimen, measuring fromthe apex,) 0-36 inch; diameter of

same

atapex 0-03 inch, do.

atlargerextremity^{0-06 inch.}

Locality

and

_position.

Moreau

_River,formationNo. 5of theNebraskasection.

Cylichna_scitula,M.

&

H. Shell small, rather thick,narrow,subelliptical, or subcylindrical; spire entirelyhidden

;

summit

_truncate,

and

occupied by a comparativelylargeumbilicoid_depression; aperture very narrow, moderately arched,

and

_equalling the greatest length of the shell

; umbilical region slightlyimpressed; inner _lip reflexed

upon

^the columella,

which

seemstobe slightly twisted, so as to form a small indistinct fold at its base; surface

marked by

fine,obscurelines ofgrowth,

which

are crossed

by

impressed, re- volving striae, separated

by

spaces about twice or three times their

own

breadth,nearthemiddleof theouter whorl, but

becoming much more

_closely

crowded

towards the extremities.

Length

^{0-24 inch}; breadth 0-14 inch;

widestpart of aperture 0-07 inch,breadth of

same

_{near upperextremity,only}

002

inch.

Locality

and

_position.

Moreau

_{River, No.}5oftheNebraskasection.

CONCHIFERA.

Teredo

selliformib, M.

&

H. Shell small, subglobose^; posterior side nar- rowly rounded above,gaping,

and

_{havinga broad,}

more

orless angular notch

[May,

NATURAL SCIENCES OP PHILADELPHIA. 179

below; antero-ventral side provided witha large hiatus,formed

by

a similar, but deeperrectangular notch,

which

extendsfromthe base nearly half

way up

to the beaks,

and

back almostto the middle ofthe valves; base,

between

the anterior

and

posterior notches,extended

downward

ⁱⁿthe form of a

narrow

prolongation,

which

curves _under,

and

isthe onlypart of the ventral borders of the

two

valves that

come

in contact

; beaks _elevated,gibbous, incurved,

and

locatedbetween themiddle

and

the anterior margin^{; surface}

ornamented by

small concentric_lines,whichare curved,

and

deflected parallel to thegreat irregularitiesof thefreeborders,

and

crossed

by two

^distinctradiatinggrooves, oneofwhich_passesfromthe

back

part of thebeaks^obliquely

downward and backward

tothe corner of the posterior notch,ari^the other nearly directly

downward

totheextremityof the ventral prolongation. Length,^{of a}

medium

sizedspecimen,^0-16inch; height 0-14 inch; gibbosity 0-13 inch.

Locality

and

_position. Fort_Clark,

on

the Missouri,ⁱⁿformationNo. 5.

Mactra

Siouxensis, M.

&

H. Internal cast oval-subtrigonal, moderately gibbous^{; anterior} border narrowly rounded; posterior

margin

subangular ^at the extremity^; base forming a nearly semiovate _{curve, the}

most

_prominent part of

which

isinfront ofthemiddle_; dorsal outline decliningwith_{a slightly} convexoutlinebehind_{the beaks,}

and

_distinctlyconcaveinfrontof

them

;beaks prominent, rather gibbous,very nearly central; pallial impression provided with anoval _sinus,

which

_appearstobealittle narrower behind than in tHe middle,roundedatthe anterior extremity,

and

_{extendingnearly}ina horizontal direction, about three-fourths of the

way

^{towards the} middle of the valves.

Length^1-55inches; height, 1*22 inches^; convexity^0-76inch.

Locality

and

_position.

Near mouth

ofBig Sioux River,ⁱⁿ formation No. 1, of the

Nebraska

Cretaceousseries.

Mactra

_gracilis, M.

&

H. Shell small, rather _thin, ovate-subtrigonal, moderately gibbous, anterior end rounded, a ^little broader than the other

;

base forming^abroad semiovate _curve,being usually

more

prominent towards the front than behind; posterior margin ^rather narrowly rounded, ^or sub- truncate; beaks moderately prominent,

and

located slightly inadvance of the middle; escutcheon comparativelylarge,lance-ovatein form; surface

marked by

distinct, regular ^lines of

growth

^: hinge

unknown. Length

^{0-49 inch};

height0-38 inch; convexity about ^{0-24 inch.}

Locality

and

_position.

On

Yellowstone _River,150 miles abovethemouth, ⁱⁿ beds containing a mingling^{of thefossilsof}No.4

and

5.

Tellina? Formosa,^M.

&

H. Shell subelliptical,verythin,moderately con vex

;anteriorextremity^alittlewider thanthe other,but very narrowly round- ed; posterior sidesubangular^attheextremity; base forminga semi-elliptical curve;

dorsum

_{sloping gradually,}witha slightlyconvex outlineinfront

and

rear; beaks_small,

and

located almost _exactly inthemiddle; ^surface

marked

byrather obscure, irregular^linesofgrowth,

and

_extremelyfineradiatingstriae,

only^visible

by

^{the aid of a} magnifier; hinge

unknown. Length

^{0*67 inch;} height 0-40 inch; convexity(of a right valve)about0*13 inch.

Locality

and

_position.

Twenty

^miles

below mouth

of

Cannon

Ball River, formation No.5.

Cyprina humilis.M.

&

H. Shell ovate, gibbous, thick,very oblique; ante- rior margin scarcely extending

beyond

^the beaks,abruptly

rounded

below;

base semiovateinoutline,

most

prominent towards^thefront,sometimesalittle contractedbehind;posteriorextremityroundingobliquely,with a broad curve fromthe

dorsum

to the postero-basal extremity,

which

isnarrowly

rounded

;

beaks very oblique, almost overhanging the anterior border, declining

and

turnedalittleinwards atthe extremities;

umbonal

_slopesprominent from near thebeaks_obliquely

backward

tothelower part of the anal

margin

; surface

marked by

distinct, subimbricating ^{lines of}growth.

Length

^{1-70 inches;} height 1-34 inches; breadth 1-30 inches.

I860.]

180 PROCEEDINGS OF THE ACADEMY OF

Locality

and

_position. North branch of

Cheyenne

River, near Black _Hills, formation No.5.

Avicula

subsibbosa, M.

k

H. Shell _(left valve) obliquely rhombic-oval, or ovate, moderately gibbous; ^anterior

margin

contracted, or a^littleconcave in outline justbelowthe wing, from

which

_point it descends _obliquely back- ward, with a broad, gentlyconvex sweep,^intothebase;posteriorborderrather broadly

rounded

below,distinctly sinuous under the

wing

^above; hinge ^line Straight,alittle less thantheheight ^{of the shell.} Anterior

wing

forming an equilateral^triangle,compressed,

and

ratherdistinct fromthe

umbo;

posterior

wing

having ^the form ofa very inequilateral triangle,the posterior sideof

which

is

much

the shortest, compressed, moderately ^distinct from the

more

gibbouspart of the valve,forming an angle^ofabout50 atthe extremity;

beak

small, slightly elevatedabovethe hinge, gibbous, located a^littlelessthan one- third the length of the hinge,behindthe anteriorextremity; posterior

muscu-

lar scar _large,oval or ovate,

and

locatedalittle above the middle. Height 1-40 inches; length, measuring from ^the postero-basal extremity obliquely forward

and upward

^{to the} point of the beak, ^{1*72 inches}; length of hinge 1-32inches.

This_speciesresembles A. linguiformis,

Evans & _Shumard,

butis

much

broad- er

and

less oblique, whileitspostero-basal margin ^is

more

broadly rounded.

Our

_specimenis a_cast,

and

doesnot

show

the surface-markings, excepting on the anterior wing,

where

the

marks

of

growth

^are rather distinct

and

subim- bricating.

Locality

and

_positio?i.

Long

Lake, above^FortPierre,formation No.5.

Inoceramus cuneatus, M.

&

H. Shell oblong-ovate,moderately gibbous ⁱⁿ the

umbonal and

anterior regions, verynearly or quite equivalve, rather thin;

buccalsidedescending from^the beaks ai _first,almost at right angles ^to the hinge,^after

which

itgraduallycurves obliquely

backward and downward,

^so astopassbya graceful

sweep

^intothebase; posterior side long, compressed, broader thanthe other extremity,

and

_regularly

rounded

; ventralborder form- ing^asemiovate_{curve, the}

most

_{prominentpart of}

which

isbehindthemiddle

;

hinge verylong,

and

_{nearlystraight. Beaks very}nearly terminal, or located almostdirectly overthe anterior border, oblique, rising^littleabove _{the hinge,} equal,

and

butslightly incurved. Surface

marked by

^rather distinct,

more

or lessregular undulations.

Length

3-90 inches; height 2-75 inches^; convexity 2inches.

Locality

and

_position. Yellow Stone _River, 150 miles above themouth, ^ia beds containing^ablending^{of thefossilsof}formationsNos. 4

and

5.

Inoceramds

_Vanuxemi, M.

&

H. Shell _large, subcircular or broad oval, equivalve,

and much

_compressed; anterior

margin

^{rounded; base} forming ^a nearly semicircular curve,being^alittle

more

prominent behind than^{in front;} posterior sidelonger and wider thanthe other,broadly rounded orsubtruncate;

hinge (ofmoderate _length?) straight,

and

forming an angle^ofabout 70 with theaxisofthe

umbones.

Beaks small, compressed,scarcely rising above the hinge,notdistinctly incurved, located a^littlein advanceof the middle. Sur- face

ornamented

_{byregular,distinct,angular,}but not_veryprominent concen- tricundulations,

which

areseparated

by

^{rather shallow} depressions. Length of the largestspecimen

we

haveseen, 10 inches; heightof do. 9 inches.

Locality

and

_position.

White

River above the

Bad

_Lands,in upperpart of formation No.4.

Inoceramus

_Balchii,M.

&

H. Shell _large, subquadrate, ^or broad oblong- oval,

much

_compressed; anterior side truncate obliquelyforward _{above, at}an angle^ofabout 115 with the hinge,rounding ^{into the} base below; ventral

margin

forming ^a broad _curve, the

most

_{prominentpart of}

which

isalittle

behindthemiddle; posterior side longer

and

wider than the other, broadly rounded, (sometimes subtruncate above?); hinge^linerather long,forming

an

[May,

NATURAL SCIENCES OF PHILADELPHIA. 181

angle ofabout 60 with the

umbonal

axis. Beaks narrow, rising

somewhat

abovethe hinge, scarcely incurved, locatedabout

halfway

^{betweenthemiddle}

and

the

most

_prominentpart of the anterior border. Surface

ornamented by

veryslightly elevated, broadlyrounded, rather irregular undulations,

which become

entirely obsoleteon_largespecimens belowthe middle, ^findon_{the pos-} terioraswell as theloweranterior regions. Attains a diameter of3j ^to 4 inches.

Named

after Lieut. G. T. Balch, of U. S.Ordinance

who

discoveredthe onlyspecimensof the species

we

haveseen.

Locality

and

_position.

White

RiverabovetheMauvaises Terres.

Inoceramus subcompressds, M.

&

H. Shell rhombic-oval, compressed, very thin

; anterior sideroundedbelowthebeaks

; base forming ^a long semiovate curve, the

most

_{prominentpart of}whichis behind the middle; posterior side long,verynarrowly rounded and prominent belowthe middle,subtruncateob- liquelyforwardabove; hinge^ofmoderatelength,forming anangle ofabout 40 withthe

umbonal

axis. Beakssmall, scarcely risingabove the hinge, located nearlyoverthe anterior extremity. Surface

ornamented

_by

somewhat

_regular concentric undulations. Length ^2-55inches; height ^1-T0inches.

Locality

and

_position.

Mouth

ofJudith _River,formation No.1? of

Nebraska

section.

Inoceramus

avicdloids, M.

&

H. Shell compressed, ^often broadovate or subcircular

when

_{young, but}

_becoming

_obliquely oval or subrhomboidal in outline asit

advanced

inage;substancethin

and

_fragile. Anterior

and

basal margins forming^abroad_gentlecurve

; posterior extremity narrowly

rounded

below, ascendingobliquely forward,with_{a slightly}convexoutline above,

and

meeting^thehinge^atan_{angle of}about

120.

_Hinge

margin

long, straight

and

compressed, ^{so asto}formanalateexpansion ^behind. Beaks nearly terminal, scarcely risingabovethe hinge, not gibbous ^or distinctly incurved. Surface ornamented by

more

orlessregular concentricundulations

and

obscure lines ofgrowth. Length from^thebeaks_obliquely

backward and downward

to the postero-basal edge, about3 inches; height from base^tohinge, 2-30 inches.

Locality

and

_position. LittleBlue_River,formationNo. 3.

Anomia

_obliqua,M.

&

H. Shell_thin,broad oval, subcircular, or

somewhat

irregular,

and more

orlessoblique; uppervalve ratherconvex,

beak

_{nearly or} quite marginal,

and

_placednearer the anterior _side,moderatelygibbous^{; sur-} face

marked

concentricallyby^fineobscure_lines,

and

smallwrinklesofgrowth.

Length about ^{1-32inches ;}breadth 1*16 inches.

Locality

and

_position. Near

mouth

of Niobrara _River, information No.3 of the

Nebraska

section.

Anomia

subtrigonalis,

M. &

H. Shell subtrigonal,approachingsubcircular, extremely^thinand_fragile; upper^valvemoderately convex; anterior side sub- truncate,witha_slightlyconvexoutline,rounding abruptly^atitsjunctionwith the ventralmargin; posterior side obliquely truncate'from _{the beak,}

and

_very narrowly rounded^atits connectionwith the ventral border,provided with ^a broad, oblique,

rounded

fold; pallial margin nearlystraight, or but slightly convex;

umbo

marginal and ^rather prominent.

Lower

valve nearly flat, or compressed,

and more

_irregular than the other. Surface

marked

_bysmall,

irregular,concentric wrinkles,

and

very obscure^{lines of}growth.

Length

^1*57 inch; breadth 1-14 inch.

Localityand_{position. Bijou Hill,}onthe Missouri,formation No. 4.

Ostrea

_inornata, M.

&

^H. Shell small,

narrow

_subovate, rather _thin, attached by^thewhole under surface of the lowervalve; beakspointed

and

curved _usuallytotheleftside; undervalveconforming ^{to the} contourof the surfaceto

which

itadhered, moderatelyconcave, area small

and narrow

;upper valve ratherconvex, having^its

beak

lesspointed than^thatof the other valve;

I860.]

182 PROCEEDINGS OF THE ACADEMY OF

surface smooth,^oronly

marked by

very obscure^linesofgrowth,^withsometimes afew verysmall, irregular, nearly obsolete radiating wrinkles nearthelower border.

Length

^about 1-40 inches; breadth 0-87 inch.

Locality

and

_position. Great

Bend

of the Missouri,below FortPierre lower part ofNo. _4,

Nebraska

section.

JURASSIC SPECIES.

CONCHIFERA.

Pholadomya

_humilis, M.

&

H. Shell transversely oblong-oval, ventricose^; posteriorend rounded,

and more

orlessgaping; basenearly straightalong^the middle; anterior end veryshort,narrowly rounded below ^thebeaks;

dorsum

nearly parallelwiththe base, slightly concavein outline; escutcheon lanceo- late,

and bounded

_by

an

obscure _angleon each side; beaks _{depressed, gib-} bous, incurved,

and

locatedinadvanceof themiddle; ^surface

ornamented by

small,regular, concentric wrinkles,crossed by^a few raised _lines, or obscure, distant,radiatingcostae, extending from^the

back

part of the beaks, to the pos- terior, andpostero-basalmargins. Length about ^1-06inch: height 0-52 inch^; breadth0-52 inch.

Locality

and

_position.

Lower

Jurassic _series, at the south-west base of the BlackHills.

Myacites Nebrascensis, M.

&

H. Shell elongate,subelliptical,ratherconvex;

extremities narrowly rounded,the posterior end being sometimes apparently obliquely subtruncate,

and more

orless gaping above^; base_nearlystraight,or veryslightly sinuous along ^the middle,rounding

up

gradually towards ^the ends;

dorsum

behindthebeaks concaveinoutline; posterior

umbonal

_slopes gibbous, ^orprominently

rounded

; antero-ventral region a little compressed, orcontracted from nearthemiddleof thebase _obliquelyforward

and upward

^; beaks moderatelyelevated,gibbous, incurved,

and

located near the anterior

end

; surface

ornamented

_byconcentric_striae,

and

_small,veryobscure, irregu- larparallel wrinkles.

Length

^{about 1-43inch}; height 0-69 inch; breadth0-59 inch.

Localityand_position. South-west base BlackHills. Jurassic.

Thracia?

sublevis,M.

&

H. Shell

narrow

oblong-oval,^rathercompressed^; anteriorend narrowly

rounded

; basenearly straightalongthe middle,round- ing

up toward

the ends

; posterior side longer thanthe other, roundedor slightly truncate,

and

_{apparently gaping}alittleat the extremity; dorsal bor- derconcave inoutline,

and

nearly horizontalbehindthe beaks, declining

more

abruptlyⁱⁿ front; beaks moderately elevated, the right one being usually a little higher thanthe other, located ⁱⁿadvance of the middle; posterior

um-

bonal_slopes prominently rounded; surface concentrically^striate; hinge

and

interior

unknown.

_Length 1-17inch; height

060

inch; breadth about0-32 inch.

Locality

and

_position.

Near

themiddleof the Jurassic deposits at the south- west base^{of the}BlackHills.

Thracia?

arcuata, M.

&

H. Shell small, transversely subovate,

more

or less arcuate,moderately convex^; extremities rather narrowly rounded,

and

a little gaping; ^cardinal margin sloping from the beaks, anterior slope

more

abrupt than^{the other;} beaks rather elevated

and

_unequal,thatof the right valve being higher thanthe other, locatedⁱⁿadvanceof themiddle; posterior

and

anterior

umbonal

_{slopesprominent;} sidesof the valves flattened or slightly concave ⁱⁿ the central regionnearthe base; ^{surface of cast} retaining small concentric

marks

of

growth

; hinge

and

interior

unknown.

_Length, 62 inch;

height, 0-37 inch

; thickness or convexity. 0-23 inch.

Localityand_position.

Same

aslast.

Cardium

Shumardi, M.

&

H. Shell small, subcircular, rather gibbous; an-

[May,

NATURAL SCIENCES OP PHILADELPHIA. ¹⁸³

teriorside

rounded

; base

more

broadly rounded^; posterior side obliquelysub- truncateabove

and

_passing with an abrupt curve^{into the} base below_; hinge margin ^rathershort,

and

_{slopingslightly}from _{the beaks,}

which

aremoderately elevated,gibbous

and

nearly central; posterior

umbonal

_slopes angular; sur- face ofcastretainingonly^tracesofsmall radiating^costae or lines on_{the pro-} minent_posterior

umbonal

_slopes,

and

flattened postero-dorsal region^; hinge

and

interior

unknown. Length

^{0-44 inch}; height 0-37 inch; thickness 0-32 inch.

Named

inhonorof Dr.

George

^G.

Shumard,

^{of the}Texas Geological Survey.

Locality

and

_{position. Jurassic,}beds south-west base ofBlackHills.

Tancredia?

jsquilateralis,M.

&

H. Shell verynearly equilateral,

mode-

ratelyconvex; anteriorendrathernarrowly rounded^; base forming ^{a broad,} regular, semielliptic curve; posteriorend_slightlytruncateontheupperoblique slope, narrowly

rounded

below, apparently^notgaping^; beaks depressed, loca- tedalittlein

advance

of themiddle; ^{surface of}cast retaining traces of con- centricstriae; hinge

and

interior

unknown.

_Length1inch_; height 0-64inch;

breadth about0-16 inch.

Locality

and

_position. South-west base Black^Hills Jurassic.

Tancredia Warrenana,

^M.

&

H. Shell small, trigonal ovate, moderately convex, ^{anteriorhalf alittle}narrower

and more

compressed than ^the other, narrowly rounded^attheextremity; base forming^a broad_gentle curve; pos- teriorside subtruncate,angular, or abruptly rounded below;

dorsum

_sloping from the beaks, the anterior slope being slightlyconcave in outline,

and

the other nearly straight, or a little convex; beaks _elevated, but notextending

much

above thecardinaledge^; posterior

umbonal

_{slopes prominent,} or sub- angular; surface

and

_hinge

unknown.

Named

in honorof Lieut. G. K.

Warren,

^U.S. Top. Engineers.

Length

^0-50inch; height 0-33inch; breadthabout

014

inch.

Locality

and

_position.

Same

as^last.

Astarte

_fragilis,

M. &

H. Shell small, ratherbroadoval,thin,moderately compressed; ^anterior end rounded; base nearly straight along ^{the middle,} rounding

up

regularly^{in front,}

and more

abruptly behind^:posteriorextremity obscurely subtruncate;

dorsum

_straight and _{slightly declining} behind the beaks,

which

are small, obtuse, rather depressed,

and

located a^littleinadvance of themiddle; posterior

umbonal

_slopes prominent; ^surface

ornamented by

distinct,irregular concentricwrinkles andfineparallel^striae;hinge and^interior

unknown

; pallial margin^{crenulate within.}

Length

^{0-45 inch;} height ^0-32 inch

; breadthorconvexity^{0-18 inch.}

Locality

and

_position. South-west base of theBlackHills Jurassic.

Astarte

inornata, M.

&

H. Shell subelliptical, compressed; extremities rounded,the posteriormargin forming ^a broader curve than _{the other;} base semiellipticalⁱⁿoutline;

dorsum

_decliningfromthe beaks, the anterior slope being^alittleconcave,

and

theother nearly straight or slightly convex; beaks moderatelyelevated,compressed, angularⁱⁿ front,located just ⁱⁿ advance of themiddle

; lunule rather deep, lance-oval,

bounded

on each side

by

^a

more

orlessdistinctangle; surface

marked by

^concentricstria?,witha tendency^to developsmall,very obscureconcentric wrinkles. Length^1-15 inches; height 0-79 inch^: breadthorconvexity^{0-44 inch.}

Localityand_position.

Same

aslast.

Trigonia Conradi, ^M.

&

H. Shell rather small, subtrigonal, moderately convex;anterior side truncate; base

rounded

; posterior side sloping obliquely frornthebeaksabove,

and

_apparentlyvertically truncate^atthe extremity;beaks elevated, narrow, incurved,

and

located in advanceof themiddle; posterior

umbonal

_slopes distinctly angular; surface

ornamented by

^{rather small,} obscure concentric_costa?,

which

onthe posterior side of the valves, descend

I860.]

184 PROCEEDINGS OP THE ACADEMY OF

atfirstperpendicularly,^after

which

_they are deflected forward _parallelto the basal

and

anterior borders. Length

and

_height, each about

097

inch; con- vexity 0-58 inch.

Locality

and

_position. Sonth-west base BlackHills,Jurassic.

Named

in honor ofMr. T. A. Conrad, ^{the well}

known

palaeontologist, of Philadelphia.

Pecten

extenuatds,

M. &

H. Shell broad _ovate, or sub-circular, thin, compressed; ^basal

mtrgin rounded;

^beaks small; hinge ^{line rather} short;

ear3

unknown

; surface apparently having only concentric striaeofgrowth.

Height 0-98 inch, length 0-90inch; convexity^{0-28 inch.}

Locality

and

_position. South-west baseofBlack_{Hills, in}asandstoneoflower Jurassic age.

PALEOZOIC.

Myalina

aviculoides, M.

&

H. Shell subtrigonal, higher than long, very convex, ^or sometimes subangular

down

the

umbonal

_slopes; anterior

margin

distinctlysinuous abovethe middle, thence descending witha slightlyconvex curve, nearly at right angleswith _{the hinge,} to thebasal extremity, which is

narrowly

rounded

; posterior side compressed, ^its

margin

curving ^{a little} forward above,or intersecting thehinge^at right angles, slightly convex,

and

nearlyperpendicular along the middle,below

which

itcurves obliquelyforward totheabruptly

rounded

basalextremity; hingestraight,nearly equalling the length of the^shell;beaks very convex, subangular, and curving^ratherabruptly forward, so as^to

become

nearly, or quite terminal^; surfacehaving moderately distinct

marks

of growth. Length, ^{1-48 inch}; height, 1-66inch; convexity, (of^leftvalve), 0-32 inch.

This ^will be _readily distinguished from ^alltheother species of the genus

known

to us,

by

^its

more

accurate_front,

and

theextension ofitsanteriormargin underthe beaks,aboveits

most

sinuous _part.

Localityend_position.

From

the upper beds, containing

Permian

_types of fossils,on

Cottonwood

_creek,

Kanzas

_Territory.

Note. Ingoingcarefullyovertheseextensivecollections,

we

haveinaddition tofinding the

new

species here described,succeededin

working

^{fromthematrix,} betterspecimens^of

many

^ofthose alreadypublished by us,than

had

been_pre- viously obtained.

The

additionalinformation derivedfrom these,

and

a

more

careful review of the subject has enabled us to

make

several corrections inthe

synonyma,

^{aswell asin}the generic references, a^listof

which

is given below.

Itwillalsobeobserved, that

we

have

made

quite a

number

ofotherchanges, in ordertorangethe speciesunderthe oldest generic

names

_proposedafterthe introduction

by

Linnaeus, of thebinomial_system.

We must

_{confess,however,} that

we

have

some

doubts whetherscienceistobe

much

benefitted

by

^astrict observanceof thelaw of _priority, in such cases as those

where

it

becomes

necessary ^to change long established names.

We

nevertheless

make some

such changes ⁱⁿconformity with usagesrapidlygaining ground,

and

_probably destinedsoonto

become

universal

amongst

conchologists

and

laborersinother departments^ofNatural_History.

The

transferof several species formerlypublished under^the

names

_Hamites, Ancylocerasl

and

Turrilites, to thegenusHelicoceras,hasbeen

made

inaccord- ance with theviewsofMr. Daniel Sharpe, (Fossil Mol. Chalk, England, part 3d, Cephalopoda, p.59, Paleont. Soc.)

who

refers allthe so called Turrilites having roundedwhorls, with the siphuncleplaced onthe dorsal or outer_side,to thegenus Helicoceras,

whether

thewhorls arein contact or not.

The

_genus

Turrilites, he restricts to thoseforms having

more

orless angular contiguous whorls,withthesiphuncle^locatednearthe suture.

The

factof thewhorlsof thoseforms withrounded volutionsbeing ^{in contact or} not, can_scarcely be

[May,

NATURAL SCIENCES OF PHILADELPHIA. 185

regarded^{inall cases, of} evenspecificimportance, ^{sinceit is}

now

well

known

thatin

some

instances the

same

species presents boththesepeculiarities,

and

sometimesthewhorlsofonepart of the spire are in contact,

and

inothersdis- connected,evenin the

same

individual.

Our

specimens confirm Mr. Sharp's views, ^foralthough they^arebut

mere

fragments,^itisevidenttheyare parts ofspiral shells, presenting intermediate gradations between forms with whorlsbarely in contact,

and

others in

which

theyare clearly disconnected.

Mr. D'Orbigny ^describes the septa of the genus Helicoceras as being un- symmetrical, ^{likethose of} Turrilites, this,however, ^isnot always ^{thecase in} species,the whorlsofwhich

make

a verybroad curve arounda large umbilical cavity,^{for in}

some

of our specimens of ^thiskind, the corresponding^lobes on opposite sidesof the siphuncle, present scarcely the slightest inequality,

and

inother instances

seem

tobe_{as nearly} symmetrical^{as in}Hamites, or

any

^of thealliedgenera.

Namesformerly^used.

Hamites Mortoni,^Hall&Meek. 1 Helicoceras tenuicostatum,Meek & Hayden. j

Turrilites (Helicoceras) cochleatus,M. &H.

Ancyloceras?Nebrascensis,Meek & Hayden.

Turrilites Nebrascensis,Meek & Hayden.

Ancyloceras?Cheyennensis, Meek & Hayden.

TurrilitesCheyennensis,Meek& Hayden.

Turrilites umbilicatus,Meek& Hayden.

Ammonitespercarinatus, Hall& Meek, presents extremely different characters, at

various stages of^itsgrowth^;probably not distinctfromA. Woolgari, of Mantell.

Ammonitescordiformis.Meek&Hayden, probably^identicalwithA.Cordatus, Sowerby.

Planorbisfragilis,*M.&H. (non Dunker.) Planorbis subumbilicatus,Meek& Hayden.

Planorbis amplexus.Meek & Hayden.

PaludinaConradi, Meek&_Hayden.

Paludinamoltilineata,Meek& Hayden.

PaludinaLeai,Meek & Hayden.

Paludinaretusa,Meek&_Mayden.

Paludinatrochiformis,Meek&_Hayden.

Turritella Moreauensis,Meek & Hayden.

Scalaria cerithiformis,Meek & Hayden.

TurboNebrascensis.Meek &_Hayden.

Rostellaria biangulata.Meek& Hayden.

Fususcontortus.Meek & Hayden.

Buccinum?vinculum, Hallk Meek.

Acteonattenuatus,Meek_{k Hayden.}

Acteonconcinnus, Hall&_{Meek, \} Avellanasubglobosa,Meek& Hayden.j

Acteonsubellipticus,Meek & Hayden.

NaticapaludinjEformis,* Hall &Meek.

(non

N

paludiniformis, D'Orbigny.) Bullasubcylindrica,*Meek & Hayden.

Corbulaventricosa,Meek & Hayden.

CorbulaMoreauensis, Meek&_Hayden.

Cythereatenuis.Hall& Meek.

Cythereapelluclda,MeekIkHayden.

Cytherea Deweyi,Meek8cHayden.

Cytherea Owenana,MeekStHayden.

Cythereaorbiculata, Meek

&

Hayden.

Cyclas Formosa,Meek& Hayden.

Cyclasfragilis, Meek & Hayden.

Cyclas subelliptica,Meek&_Hayden.

Hettangia Americana, Meek & Hayden.

Nucula Evansi,Meek&_Hayden.

Nucula scitula,Meek & Hayden.

Cucull^aShumardi,Meek & Hayden.

Pectunculus Siouxensis, Hall&Meek.

Pectunculussubimbricatus, Meek& Hayden.

Nameshere adopted.

Helicoceras Mortoni.

Helicoceras cochleatum.

Helicoceras Nebrascense.

HelicocerasCheyennense.

Helicoceras umbilicatum.

Planorris planoconvexus.

Valvata subumbilicata.

Helix (Polygyra) amplexus.

Vivipara Conradi.

vlviparamultilineata.

Vivipara Leai.

Vivipara retusa.

Vivipara trochiformis.

Cerithiopsis Moreauensis.'

Turbonilla(Chemnitizia) cerithiformis.

Margarita Nebrascensis.

Aporrhaisbiangulatus.

Pleurotoma contorta.

Fusus vinculum.

Solidulus attenuatus.

Avellanaconcinna.

Solidulus (Acteonina?)subellipticus.

Amadropsis paludiniformis.

Bullaspeciosa.

Ne^raventricosa.

Ne^raMoreauensis.

Meretrix^tenuis.

Meretrixpellucida.

Meretrix Deweyi.

Meretrix Owenana.

Meretrixorbiculata.

Sph^erium formosum.

sph.erium fragile.

sph.erium subellipticum.

Tancredia Americana.

LedaEvansi.

IiEDA SCITULA.

Cucull^a fibrosa,Sowerby.

AXW.EASiouxensis.

AXIN.SAsubimbricata.

I860.]

*The namesfollowedby anasterisk,werepre-occupied.