Proceedings of the United States National Museum

THEOSTEOLOGICAL CHARACTERISTICS OF THE FAMILY ANGUIL-

LIDJE.

KV

Theodore

^Gill, M. D., Ph. D.

The

diversities within the restricted

Apodes

^(or those anguilliform fishes without developed interrnaxillaries

and

with the

"vomer"

pro- jecting

and

forming, with the supramaxillaries, theupperarcade of the mouth) are very great, but were not appreciated till Professor

Cope

considered

them

inhis^'•ObservationsontheSystematicdelations of the Fishes."* That great naturalist

was

so impressed

by them

that he distributed

them

undertwo orders, the EnchelycephaU,i embracing the Congridce, Anguillidce,

and

Murcenesocidce,andtheCf>locephali,\ iuc\\i(\\ng theMurccnidw

and

Ratahitridfv {

=

Morin{juidw).

While

I

am

not pre- paredyetto admitthe "orders" of Professor Cope, Iretain thegroups as suborders with modified characters,

and

the families appear not only to be justified, but, it seems to me,

must

be increased.

A

com- parison of the skulls of Anguilla, Conger, Murcenesox, Simenchelys, Syna])hobranchu8, Ophichthys,

and

Murcena hasconvinced

me

ofthead- visability ofrecognizingforeach of

them

family rank.

The

characters ofthe familyAngiiillidcecontrasting with oneor otherof the other fam-

ilies are

now

given in the order which I haveheretofore

employed

for full descriptions offamiliesofnormalfishes.

ANGUILLIDiE.

Synonymsasfamilynames.

<[ Pantopt<>re8,Dum^ril,Zool.Anal.,_pp. Ill, 11.'), 1806.

<^ Anguillidi, Rafinesque, Indiced'lttiolog. Siciliana, p. 37, 1810.

<^Pantopteria,Bafinesqae, AnalysedelaNature,^2'.'>fain.,j).

—

, 1815.

<

Anguilliformes, Cuvier,RfegneAnimal^[1"6(1.],t.2, p.229,1817; 2« ^d.,t.2,p. 348, 1829.

<

Anguilloides,Latreille,Fain.Nat.,Rf^gne An.,p.142, 1825.

<[Le3Miir^nides,Risso, Hist. Nat.Europeni6rid.,_{t. 3,}p. 169,1826.

<;Mura;nida},^o«rt/?ar<e,Giorn.Accad.diScienze, v..'>2 (Saggio Distrib. Metod.Ani- mal) Vertebr. aSangueFreddo, p.34), 1832.

<

Munenidfo, Bonaparte,Nuovi AnnalidelleSci.Nat.,t.2,p.133,1838;t. 4,p.276,1840,

<^Mura)nid;e,Sivainson, Nat.Hist,andClass.Fishes,etc., v.2,pp.195,333, 1839.

<

AnguiUares, Miiller, Archivf. Naturge8ch.,9..Jg.,B. l,p. 328, 1843.

<Munenidie,Bonaparte, Cat. Metod. Pesci Europei,p. G",38*, 1846.

<

Murajnidaj,Adams, Man.Nat. Hist., p. 110, 1854.

• Proc.Am. Aks. Adv.Science1871, v.20, pp. ^317-:{43,1872.

t Oj).dt.,p. 334.

Proceedings NationalMuseam,Vol.XIII—No.803.

157

158 OSTEOLOGY OF ANGUILLID^E

GILL.

=

AnguillidfB,Kaup, Arcbivf. Naturgesch.,22.Jg., B. l,p.54,1856.

=

AnguillidPB, Eaup,Cat. Apod.FishB.M.,p. 32,1856.

=

Anguillidae, Richardson,Eiic.Brit.8tbed.,v. 12, p.232, 1856.

=

Auguilloidei, Bleeker,Enum.Sp. PisciumArchipel. Indico,p. xxxiii, 1859.

<

Anguilloidei, Encr, Sitzungsb.k.Akad. Wissenscb.(Wien),v.42, p.1,1860.

<Mura}uid0P, GUnther, Cat. FishesBrit. Mus.,v.8,p. 19,1870.

=

Angnillidse, Cope,Proc. Am.Assoc. Adv. Sci.,v.20,p. 334, 1872.

=

Anguillidae, Gill,ArrangementFam. Fishes, p. 20, 1872.

<^ Anguilla^,FUzinger,Sitzguugsber.k.Akad.der Wissenscb. (Wien),B.67,1.Abth., p.45,1873.

;=Mur0Bnidi, Poey, Anal. Soc. Esp.Hist. Nat.,v. 4, p. 10,1875.

<^Anguillidse,Mor€au,Ii\6t. Nat.Poiss.France,v.3,p.560, 1881.

<

Anguillida", Jordan4-Gilbert,Syn. Fishes N.Am.,p.357, 1882.

—

Anguillidai,Gill,StandardNat.Hist.,v.3,p. 101, 1885.

=

Anguillidae,Jordan,An. Rep.Com.Fish,for 1885,p.843,1887 (Sep.,p.55,1885).

=

Anguillidae,Jordan, Man.Vertebrates North. U.S.,5thed., p. 89,1888.

Synonymsassubfamily names.

<[Anguillinia,Bafine^qiie,Analyse delaNature,p.

—

^,1815.

<

^{Mursenini,Bonaparte,NuoviAunalid. Sci.Nat.,t. 2,p.1.33,1838; t. 4,p.276, 1840.}

<^ Anguillinse, Sivainson,Nat.Hist,andClass.Fishes,etc!,v. 1,p.220, 1838.

<

Anguillini,Bonaparte, Cat.Metod.PesciEuropei,p. 6*,38*, 1846.

=

Anguillina?,Eaup, Archivf.Naturgesch.,22. Jg., B.1,p.54, 1856.

<

Anguilliua, GUnther,Cat. FishesB.M.,v.8,pp.20, 23, 1870.

=

Anguillinse,Jordan

^

^Gilbert,Syn. Fishes N.A.,p.357, 1882.

DIAGNOSIS.

EnchelycephalousApodalswith conic head, well developedopercular apparatus, lateralmaxillines, cardiform teeth, distincttongue, vertical lateralbranchialapertures, continuous verticalfins withthe dorsal far from thehead, pectoralswell developed,scaly skin,

and

nearly perfect branchial skeleton.

Description.

Body

typically anguilliform, anteriorly subcylindrical, compressed behind, robust

and

with thecaudal portion gradually attenuated back- wards,

and

with the anus in the anteriorhalf of thelength.

Scales small, linearorelongated elliptical,distant,arranged insmall groupsobliquely atright angles tothose of theneighboringgroups.

Lateralline distinct.

Head

^moderate,oblongconic,withall the bonesinvested in themus- cles or skins.

Eyes

within the anteriorhalfofthehead, directed sideways, of

mod-

eratesize; notcovered

by

theskin.

Nostrilsmostlylateral5 theposterior directlyin frontof theeyes,the anteriornear themarginof the snout

and

tubular.

Mouth

with thecleftslightlyoblique,extending below^orlittlebehind theeves.

Jaws

well developed5 maxillines approximated to the frontof the

""^isgo"']

TROCEEDINGS OF THE NATIONAL MUSEUM. 159

vomer, with the clampiDg processes^selliform

and

appressed closely to the sides of the ethino-

vomer

behind itshead, with ledge-like exten- sions within,

and

attenuated backwards.

Mandible moderatelystout; thedentary with the coronoid process well developednear itsposteriorend; thearticularlittle producedex- ternally in front of the condyle, but considerablyextended

backwards and

below.

Teeth^{conic, in cardiform}

bands

on thejaws and vomer.

Lipsthick, mostly with free lateral mai^ins, but undifferentiated in front.

Tongue

welldeveloped

and

free atitsanteriorportion as well^assides.

Periorbitalbones moderatelydeveloped.

Opercular apparatus^welldeveloped; operculumlamelliform

and

ob- long,insertedhigh

up

on thehyomandibular; suboperculum falciform, bordering theoperculum; interoperculum large,.partly covered

by

the preoperculum_; preoperculumwelldeveloped, lamelliform.

Branchial apertures lateralverticalslitsiufrontof

and

lowerthanthe inferiorrays of the pectoralfins.

Branchiostegal rays in moderate

number

(about twelve),

some

at- tached to the ceratohjal

aud

others totheepihyals, quite robust

and much

bowed.

Dorsal, anal,

and

caudal confluent in one uninterrupted fin withthe raysreadilyperceptible through the thin skin; dorsal

commencing

^far behindthehead

and

littlebefore the anus; analclose behind the anus

;

caudaljirominent.

Pectorals welldeveloped, nearerthe breast than back, with the rays distinct, unbranched,

and

articulated.

Branchialarches nearly complete,withwelldevelopedglossohyal

and

urohyal,but withthe first

and

secondbasibranchials onlyossified; the

first

and

second hypobranchialsossified,third

and

fourth cartilaginous;

ceratobranchials

and

epibranchials, of four pairs, ossified; pharyngo- branchials offirst

and

secondpairs, rod-like; ofthird

and

fourthpairs, incloseapposition

and

developedasdentigerous epipharyngeals; hypo- pharyngeals oblong

and

closelyapposed

and

superincumbent on arudi-

mentary

fifth arch, covered withcardiform teeth. Interbranchialslits

extended.

Thereare

numerous

other characterswhichsupjjortthe familydistinc- tionof the Anguillidse,butthe only ones that need be here

added

are the separation of the

two

frontals, the oblique,forward trend of the suspensorium,

and

themoderatedevelopment ofthehyomandibular.

Only

one genusof the family is

known —

that generallycalled An- guiUa, but also

by

Bleeker

and some

others

endowed

with the

name

3hira'na.

Anguillais generallyascribed

by

authorsto "Thunberg," but without any definitereference to placeofpublication. Agassiz,in his

"Nomen-

clator Zoologicus," refers to "Anguilla, Thimb., Nuov.

Mem.

Stock.,

160 OSTEOLOGY OF ANGUILLIDiE

—

GILL.

179-,"

and

Giiiither to "Anguilla(Tliuuberg)Cuv.

Eegne

Anim."; but

no

such

uame

istobe found iu the

Memoirs

of the Stockholm

Academy.

The

firstdivisionoftheohl genns,Murcena appearstohave been

made by Thuuberg

or

Ahl

In 1789 in an inaugural dissertation.* Therein the genus Murccna is subdivided into,

Murwna

restricted to species without pectoral fins,

and

OpliiGlithus proposed for those with such

fins.

The

speciesenumerated are asfollows

:

Miirseua. OphicMhus.

1. M. lielenaL. 1. O. opliis.

2. M. nebulosa. 2. O. serpens.

3. M. picta. 3. O. ciuereus.

4. M. anuulata. 4. O. myrns.

5. M. fasciata. 5. O. conger.

6. O. anguilla.

The name Murwna was

thus definitely restricted to species without pectoralfins,

and

therefore the subsequentrestrictionof ittospecies with pectoralfins,

and

especially to

M.

anguilla, as Professors Jordan and Gilbert! have already shown,

was

illegitimate. If not belonging to OphicMhus, it

was

necessary, consequently, that another generic

name

should begiventothe Anguilla. Ophichthus,indeed, provedtobe a very incongruousgroup, each species representing a peculiargenus.

Genera

were proposedfor

them

as follows

:

O. opMs. Ophichtbys,Ahl., 1789.

O. serpens. LeptognatliusSw.1839.}:

O. cinerens. Munenesox, McCl., 1843.

O. myrus. MyrnsKanp.,1856.

O. conger. Conger,Cuv., 1817.

O. anguilla. AnguillaShaw,1803,

The name

Anguillatherefore rightlybelongs tothedivision sonamed, but (unlessthere is

some memoir

that hasbeen overlooked)

must

be creditedto

Shaw and

notThuuberg.

The synonymy

of thegenuswill

thenbe,in brief,as follows

:

ANGUILLA.

<

Anguilla Shaw, Gen.Zool., v. 4,p.15, 1803.

<^AnguillaCuvier, Rfeo;uo,Animal, v.2, p. 230, 1817.

=

^{AnguillaKaiq),Cat.} ApodalFish,p. 32,1856.

=

Muia3naBleelxrAtlas, Ich.Ind. Neerlaud,v.4, p. 1,1864.

Muraniasp.anct. vet.

Ophichthussp.Thunberg, Ahl.

*Specimen ichthyologicura de Miinvna et Ophichtho quod seria exp. fac. nied.

Ups.iira^sid. Carol Vet. Thunberg lequite,etc. modeste ofl'crt JonasNicol. Ahl.27.

Jan. 1739. Upsalia.

tOn the nomenclatureof the genus Ophichthus <^Proc. U. S. Nat. Mus.,v.5,pp.

648-651.

XSeeJordan«& Gilbert, op. cit.