Description of a very large fossil gasteropod from the state of Puebla, Mexico

140 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM.

Pinos, nearMonterey. It isfound mostlyinmassesof Fucusattached to rocks between tide-marks,

and

it isoften found atlowtide atacon- siderable distance from

any

water, kept

damp by

the massesof algae.

Sometimes a dozen of

them

can be shaken from a

bunch

of algse attachedto a dryrock. Itis,like the speciesof Xiphister,veryactive,

moving

over stones or sand,

and

showing less anxietyaboutthex)res-

ence of itsnativeelement than

any

;therfish

known

^{to us.}

The

very

numerous

typical examples are all of nearly the

same

sizeas the one measured below. Itprobablydoes not attain so great a sizeas Apo- dichihys Jiavidus.

We

^{have littledoubt} that ProfessorGillisright in unitingjiavidus Girard, virescens Ayres,

and

sanguineus Gill as one species.

Whether

inornatusGillisdiiferent ornot

we

do notknow.

At any

rate,its

num-

ber offin-rays (D.

XC,

A. 38) will separateitfrom A.fucoruni.

Table of measurements.

Extremelenfftli,ininches Lengthtobaseofcaudal

=

100 Body,greatestdepth Head

:

Length

Distancefrom snouttonape Dorsal,distancefrom snout Anal

:

Distancefrom snout Heightotspine Lengthofpectoral Dorsal rays

Analrays

Monterey,

Cal.,April 7, 1880

A.Jiavidus.

8.90

H

8.50 11

6 11.5 60

4 4 93 40

JDESCBIPTIOIV

OF A TEKY LAROG

^FOSSII.

OASTEBOPOD FKOM THE STATE OF FUEB1,A,

JAEX1€0.

By

C. A.

WHITE.

The

United States National

Museum

has received from Mr. H. B.

Acton, through the

Hon.

J.

W.

Foster, United States minister to Mexico, theveryinterestingfossilshellwhichisdescribedinthe follow- ing paragraphs. Mr.

Acton

says,inaletteraccompanyingthesj^ecimen, thatit

was

obtained from the strata

upon

whicharelocatedthe Zapo-

titlanSalt

Works,

which works areaboutsixmilessouthwestward from the

town

of Tehuacan, in the State of Puebla, Mexico,

and

about 115 milesinland fromtheGulf coast.

He

gives theelevation of thatlocal- ityas 6,50U feetabovethe level of thesea.

Only one example of this species has beenreceived,

and

itisaccom- panied with examples of no other species.

Fragments

of the imbed- dingrock, whichis adense bluishlimestone, have been carefully exam- ined,

and

although they were foundto contain

numerous

fragmentsof

PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 141

fossil shells,not

any

of tliemweresufficientlywell preservedto indicate eveu their generic relations.

No

satisfactory information has been obtained concerning

any

geological observations that

may

have been

made

in thatregion,whichmight conveyaknowledgeof thegeological ageof the strata of the locality from which the fossilinquestion

was

obtained,

and

I

am

therefore under the necessity of relying wholly

upon

the testimony afforded

by

the fossil itself.

The

genus to whichI have referred it has hitherto been

known

onlyinrocks of Cretaceous age;

and

thereappears to be no good reason to doubt that the strata from whichthis Mexican shell

was

obtained belongalso tothatperiod.

Genus TYLOSTOMA

Sharpe.

Tylostoma princeps

(sp. nov.).

(PlateII, figs. 1and2.)

Shell very large, general form rhombic-ovate, inflated; spiremoder- atelyextended; volutions fiveorsix, convex, having anill-definednar-

row

shoulderingatthe distalor upper portion, adjacenttothe suture;

umbilicus none, suture impressed; aperture ovate-semilunate,large, its

length equal to

more

thantwo-thirds the full length of the shell; outer lipforming an approximatelyregularcurvefrom near the sutureto the anterior portion of the aperture, which, although broad, is

somewhat

produced; margin ofthe outer lip onlyslightly sinuate; innerlip bear- ing a broad,moderately thincallus, its outline

somewhat

strongly sin- uate

and

itsmargin narrowly flexed along itsanterior portion.

Surface

marked by

theordinarylines of growth.

Length

from the apexto thefront marginof the aperture,220 milli- meters; greatestbreadth, 160 millimeters; length of aperture, 150 mil- limeters. (Museum, No. 8804.)

Thisis

much

the largestfossil gasteropod that has everbeen found in North

American

Mesozoic strata;

and

it is excelled insize

by

only comparatively fewof itsclassthat havesince existed.

Ithas

much

the general aspect of a Limatia^butit isreferred with- out

much

hesitation to the genus Tylostoma Sharjie. This last-named genus is regarded

by some

malacologists as having affinitieswith the Tectibranchiata, nearPterodonta; but Iagreewith Stoliczska

and

Zit- tel inreferring it to the Pectinibranchiata, and placingitnear Lunafia inthe Naticidfe. Itistrue thatall thecharacteristics of Tylostoma, as enumerated

by

Sharj)e

and

characteristic of mostif not allthespecies which have beenreferred to thatgenus,are notclearlyobservableupon the only examjile ofthis species that has been discovered^; but being plainlywithoutan umbilicus, oranyumbilicali)erforation, inconnection withits other characteristics, itcannot be referred to anyother recog- nized genus of theNaticidte.

The

conditionof ourexampleisnotsuch asto

show

clearly whether or not the outer lii)

was

thickenedatthe time of thedeath of the mollusk.

142 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM.

The

varices or alternate swellings, characteristic of Tylosfoma, are present, but not so conspicuous

upon

this exami^le as theyare

upon some

species of the genus, especially uj^on T.mutahiUs Gabb, another

Mexican

Cretaceous form; but they are quite as conspicuous as they are

shown

tobeinthe publishedfigures of Sharpe'styp6 species, T. tor- ruhice. Thesevarices or swellings are

more

apparent in our example

by

anapical than

by

a lateralviewof it, buttheir i^reseuceisindicated infig. 2

upon

the ultimate

and

penultimate whorls.

Although sizecannot generallybe relied

upon

as aspecific character, theextraordinarydimensions of this shell separateit clearlyfrom

any

other

known

formwith whichit might beotherwisein dangerof being confounded.

The

onlyfossil specieswhich resembleit, oreven ai)iirox- imatelyapproach it in size,arethe NaiieapedernaUs?i\\([N.priv-(irmidis of Eoemer, from the Cretaceous of Texas; but both these species evi- dentlybelong to agroup that is

now

generally referred toLunatia, or Euspira;

and

tlielargest

known

examples ofeitheroftheseforms have scarcely

more

than half thedimensionsofthe examx)le heredescribed.

DESCRIPTIOIV OF TWO IVEAVSPEtlES OF 8FBASTICIITnY!^ (SEBA- ST1CD5TBIVS ExXTOMEtiA,** X^ia SEBAS^TICHl'IlYS RfllODOCH1.0- RIS), FROM IT10NTKRE¥ RA¥,€AI.IFORIMlA.

By DAVID

S.

JORDAN and CHARLES H. OILBERT.

Sebastichthysentomelassp.nov.

Allied to*S'.ovaJis(Ayres).

Body

oblong, rather elongate, the

back

regularly but not strongly arched, contracted to a rather slender caudal peduncle.

Head

moder-

ate, the i^rofile less steep than in related species, but the tip of the snout blunterthanin ovalis.

Mouth

small,the short maxillary extend- ing tobelowthe middleof theeye.

Lower jaw

projecting,itstipenter- ing the profile,but considerablyless protruding than in ovalis. Pal- atineteeth few.

Preorbitalvery narrow, without spine.

Eye

rather large, about4in length of head, less than the interorbitalspace,which is stronglycon- vex, especially initsmiddle part.

Nasals])inesminute. Preocular spine broad,triangular,ratherprom- inent,

more

conspicuous than in mclanops. but

much

less so than in ovalis. Sui»raocular ridgelittledeveloped,itsspine minute, sharp, con- cealed

by

the scales. Postocular spine present, minute, similarlycon- cealed.

No

tympanic spine. Occipital ridges scarcely developed, concealed

by

the scales,without distinct spine at tip. In ovalis all

these spines, though small,are distinct. InJiai'idusthereisnotrace of

any

spineson the cranium, and the ridgesarelittle developed.

Preopercular spines rathersmall, diiected backwards, the

two

lower obsolete. Oxjercularsx)iuessmall,two suprascapularspines. Scaleson