TELEOSTOMI

Order CROSSOPTERYGII.

The

larger

number

of remainsof"fringe-finned ganoids"belong- ingtotheUnitedStatesNational

Museum

collectionconsists ofRhizo- dont scales (14 of

them

being types described

by

Cope and others), small Coelacanths,and

more

orless completeskeletonsof Palaeoni- scids, all preserved within concretionsfrom thewell-known

Mazon

Creeklocality

m Grundy

Comity, Illinois.

Most

of these nodules were formerly contained hi the Lacoe collection, acquired

by

the

Museum

about twenty years ago.

The

Lesquereux collection

was

especially rich

m

^{fossilsfromthe}CoalMeasuresofLinton, Ohio, and most of the fishesfrom thislocaUty areCoelacanths.

The

so- called ichthyic genus and species, Myderoys orcinatus

Cope

^{^}from the CoalMeasuresofBeaver County,Pennsylvania, isnot ofverte- brate nature, but founded

upon

arachnid fragments.

The

type is cataloguedasNo.1977,andanotherspecimenidentified asa jugular plate ofCoelacaiithus

by

Jaekel,iscataloguedasNo.1975.

Family

COELACANTHIDAE.

Genus

COELACANTHUS

Agassiz.

The

earliest

known

representative of this genus is a small form occurrmg in the basal

member

^{of the}

Upper

Devoniannear Gerol- stem, in Rhenish Prussia, first described

by

the late Prof. A. von

Koenen^ m

1895,and recognized as a true Coelacanth

by

Smith

Woodward^

ⁱⁿ1898.

A

single species, C. weUeri,has been described

by

the present writerfromthe baseoftheKinderhooklimestonenear Burlington, Iowa,and twospecies of thisandapecuharalliedgenus, PalaeophicJithys,have been

made

laiownfrom

remams

preserved in nodulesfound atthefamous

Mazon

CreeklocaUtyin lUinois.

In the PalaeontologyofOhio(vol.1, 1873)twenty-sevenspecies of fossilfishes aredescribed from the CoalMeasures of Linton, Ohio, and

among

the

number

arethreebelongingto thegenusCoelacanthus.

It is stated

by Newberry

^* that the secondmost abundant species

'Amer.Naturalist, vol. 20, 1886, p. 1029.

2Koenen,A. von. Ueber^einigeFischrestedosnorddeutschenund bohmischenDevons. Abhandl.

Ges.Wiss. Gottingen, phys.01.,vol.40,1S95, p.28.

3Woodward,A.S. Noteon aDevonianCoelacanthfish. Geol.Mag.,vol.5,1898, p. 529.

*Newberry,J.S. ThePaleozoicFishesofNorthAmerica,Monogr. U.S.Geol.Survey,vol.16,1889, p. 213.

NO.2177. FOSSIL

FISHES

IN

NATIONAL MUSEUM— EASTMAN. 271

occurring at this locality is Coelacanthus elegans; and this author remarks

:

While perhapsathousandspecimens mo-eor lessperfecthave been taken from onecoalminethere,withtheexception ofa singleone foundatMorris(Illinois), norepresentativeof thisworld-widegenushasbeenelsewhere seen inAmerica

At

the conclusion of thevolumejust cited

Newberry

recordsthis additionalobservationinregardto Coelacanthusornatus:

Thisisa small speciesfoundatLinton, Ohio,whereit isveryrare. Itisbriefly described in the PalaeontologyofOhio,vol.1,p. 340. Since the publicationofthat volumeIhaveobtained several otherspecimensandfind thatitmaybereadily identi- fiedbyitssmallsize,relativelylargecranialtubercles,and verythin,delicatescales onwhich theraised linesareparalleland do not convergeasinC.elegansand C.

robustus.

Again,atpage215ofthe

same

work, the author remarks:

Since the noticeoftheMazonCreekfisheswaspublished in the reportoftheIllinois GeologicalSurveyIhavereceivedfromthere a singlespecimen eachofEurylepisand Coelacantliv^,probablynot distinctfromthosefoundatLinton.

It thus appears from the writmgs of

Newberry

that

among

the large

number

of

Mazon

Creeknodulesexamined

by

him, only asin- glespecmien ofCoelacanthus

came

underhis observation, andthat heidentifiedasbelongingto C. elegans.

An

alUed smallspecies

was

described

by

the present writerin 1903, anda supposed

new

form oflarge sizehas recentlybeendiscovered

by

Prof.E.

H.

Barbourin the CoalMeasuresofNebraska.

COELACANTHUS ELEGANSNewberry.

Plate9,figs. 5, 6;plate11, figs. 3,4.

Probably to this speciesshouldbereferred ahalfdozenspecimens in the United States National

Museum

collection, all

much

dis- torted and imperfect, but agreeing _{in scale} characters and details of ornamentation of cranial plates with C. elegans. Tlie fact that

Newberry

recognized the occurrence of this species at the

Mazon

Creek locality increases the probability that

we

have really to do witha form already

known

from Lmton, Ohio, instead of with an undescribed representative of the genus. Tlie specimensfio-m-ed in theaccompanyingplatesare cataloguedimderthe followingnumbers 4381, 4383,4405,4438.

Formation and locality.

—

Coal Measm^es,

Mazon

Creek, Illinois.

COELACANTHUSEXIGUUSEastman.

Plate10,fig.1.

Coelacanthus exiguusEastman,Journ.GeoL,vol. 10, 1902, p. 538,textfig.3;Bull.

Mus.Comp.Zool., vol. 39, 1903, p. 189, pi.5, fig.48.

Thisis a smaU-sizedspecies,none ofthe

Imown

examples exceed- ing 5 cm. in total length.

The

typeand nine other specimens -are

272 PROCEEDINGS OF THE NATIONAL MUSEUM.

vol.52.

preservedin the

Peabody Museum;

a singlespecimenisfoundinthe

Museum

^ofComparative Zoologyat

Harvard

College,and twoothers, bothin counterpartand verywellpreserved,arethepropertyofthe UnitedStates National

Museum. They

wereformerlyintheLacoe collection, and one of

them

bears an original label in Newberry's handwriting which reads: "Palaeoniscus gracilis"New.'^ Itis cata- logued as No. 4398, and is the origmal of our plate 10, figure 1.

Whereas m

^thetype-specimen only about

nme

caudalfin-raysare to be counted above and below, this specimen shows at least thirteen inthelowerlobe.

Formation andlocality.

—

^{CoalMeasures;}

^Mazon

^{Creek,Illinois.}

Genus

PALAEOPHICHTHYS

Eastman.

Thispeculiarcrossoptcrygiangenus hasbeenprovisionally referred tothe Coelacanthidge,butisdistinguishedfromallother

members

of thefamily

by

itselongate, anguilliform

body

andcontinuousmedian

fins. In the latter respect an agreement is to be noted with the specialized and problematical genusTarrasius,from the

Lower

Car- boniferous of Scotland, and alsowithConcliopoma gadiforme Kjier, fromthe

Lower

Permian of RhenishPrussia. PossiblybothTarra- siusand Conchopomashouldberegardedas aberrant Coelacanths.

PALAEOPmCHTHYSPARVULUSEastman.

riate10,fig.2.

Palaeophichthys parvulusEastman,Ann. Rept. IowaGeol. Surv.,vol. 18, 1908, p. 253,^fig.37.

Thisisaverysmallspecies, attainingatotallengthofabout5cm., with a remarkably short head and slender, elongated, anguilliform body.

The

medianfinsarecontinuous, thedorsal arisingbehindthe occiput at a distance equal to about one-and-one-half times the lengthoftheheaditself, andtheorigin ofthe analnotfarbehindthe middleofthebody.

Besidestheholotypeof thisinterestingsmallspecies, butasingle example has

come

underthewriter's observation. Itis aspecimen formerly in the Lacoe collection,

now

^the property of the United States National

Museum,

and catalogued as No. 4453.

The

nodule inwhichitiscontainedwouldseemtohave beenfractured

by

natural

means

and to have been exposed to atmospheric agencies for a considerable time, thus permitting oxidation totake place over the surface with consequent obliteration of a good

many

structural details. Thus, theprecise

pomt

oforigin ofthemedianfinsisindeter- minable, thehead bones are confused, and although the neuraland haemalarches are clearlyindicated

m

theanterior half ofthe trunk, they cease to be visible in the caudalregion.

Under

thelens itis

NO. 2177. FOSSIL

FISHES

IN

NATIONAL MUSEUM— EASTMAN. 273

possible torecognizefainttraces ofthesquamation, thescalesappear- ingtobe verysmallandcoveredwithdelicatelongitudinalstriae.

A

portion of the lateral line scale-row is indicated

by

characteristic raised markings in the posterior part of the trunk, but the caudal extremity is not distinctly shown. Apparently the tail tapered gradually to a point, without beingproduced into asupplementary caudal fui.

The sum

total of morphological features presented

by

thispeculiargenusandspeciesisofextremeinterest.

Formation and locality.

—

^{Coal Measures;}

^Mazon

^{Creek, Illinois.}

Family

PALAEONISCIDAE.

The

earliestrepresentativeof thisfamily,andofprimitive sturgeons generally, is the genus Chcirolepis, remarkable for its small-sized squamation.

A

^{singlespeciesis}

^known

^{from theDevonianrocks of}

North America, described

by

Whiteaves as Chdrolejns canxidensis.

Threespecies ofPalaeoniscus have also beenfounded

upon

isolated scalesoccurringin the

Upper

Devonianof

New York

State. These have been

named

P. antiquus and P. reticvlatus Williams, and P.

devonicusClarke,buttheyare

more

properly assignabletoRhadinich- ihys.

Genus

RHADmiCHTHYS

Traquair.

This genus, apparently indicated

by

isolated scale patches in the

Upper

Devonian rocks of this country, and represented

by

several species inthe

Lower

Carboniferousof

New

Brmiswick andtheUnited States, persists as late as the Pemisylvanian in this country.

One

species,R.deani,occurringatthebaseoftheWaverly,isremarkable forhaving yielded the first information

we

possess concerning the organization of thebrain and internal ear of any fossil fish. Since the beautifully presei-ved

bram

structure of this species was first described,^similarremainshave been foundintheCoalMeasuresnear Lawrence, Kansas,- and less well-preservedspecimens are also con- tainedinthecollection offossilsfrom theCaneyshaleofOklahoma, alreadyreferredto.

One

of thespecimensfrom thelatter localityshowingtheinternal structureof thehead of asmallPalaeoniscid,presumably ofBhadi- nichtJiys,iscataloguedas No. 8111,andanothershowingthe greater partofadentigerousmandiblebears the

number

8112.

1Ann.Kept.IowaGeol.Surv., vol.IS,1908,pp. 265-272.

2Twenhofel,W.H.,and Dunbar,C.O. Nodules withfishesfrom the Coal MeasuresofKansas. Amer.

loum.Sci.,vol. 38, 1914,pp.157-163. Moodie, R.L. Anewfishhrainfrom the Coal MeasuresofKansas, with a reviewofotherfossilbrains. Joum. Comp.Neurology,vol. 25, 1915,pp.^135-181.

65008°—Proc.N.M.vol.52—17 18