FISHES FROM SOUTHERN CALIFORNIA— GILBERT. 343 AVERRUNCUS EMMELANE Jordan and Starks

Xystes axinophrysJordanand Starks,Proc.Cal.Acad.Sci.,eer. 2,vol._5,1895, p. 824, pi. 92.

Station 4520, Monterey Bay, 32-44fathoms.

A

single

young

specimen from^theabovestation affords a notable extension in the range of this species,

known

hitherto only from Puget Sound.

The

fin-rays are as follows: Dorsal, X, 8; anal, 12;

pectoral, 14; ventral, I^2.

Examination^ofthe type of XystesaxinophrysJordanand Starks has

shown

thatitisbased ona very

young

^{individualofAverruncus} emmelane.^

The

onlyfullcharacterizationofXystesisthat given

by

Jordan and Evermann.^ Itissaid todifferfrom Averruncus

by

the shorter vertical fins, the last rays of which are without posterior

membrane;

the progressively shortened lower rays ^ofthepectorals;

the absence ofbarbelsornuchalpit; the presenceofa strongknife- like spine above eye.

The

vertical fins are, however, of the

same

length, thefinformula agreeing exactly (theanalfininthe typeof Xysteshaving 11 instead of 10 rays).

The

last rays of dorsalfins areattached

by

posterior

membrane,

asin relatedforms, this

mem-

brane rupturedinthe type ofXystes.

The

lower pectoral rays are progressively shortenedinthe

young

ofallAgonoids, a specimenof A. emmelane from Annette ^{Island, Alaska, 105}

mm.

long, showing asyetnotrace of the elongation^of these rays. Barbelsarepresent inthe typeof

X.

axinoylirys,covering the lower jaw and thebran- chiostegal

membranes

and agreeing in position with those in A.

emmelane.

A

nuchalpit is present, thoughless developed thanin adults. All thespineson head are larger intheyoung, butthosein

X.

axinopJirijs agree wholly in

number

and positionwith those in A. emmelane. There can be no doubt ^{of the identity of the} two species.

Averruncus sterlctus Gilbert should probably be referred to the genus Agonopsis, which appears to differ from Averruncus in the shorter vertical^finsandthe subequal jaws, therostrumnot conspicu- ously protruding.

The

lattercharacter is not very important, and thetwogenera eventually

may

beunited.

ASTEROTHECA, new genus

(Agonidae).

Typeof^thegenus.

—

XenochiruspentacantJius Gilbert^{.^}

Like Xeneretmus (for Xenochirus Gilbert, preoccupied) in all respectsexcept that the terminalrostral plateisverysmall, not pro- jecting beyond the premaxillaries, and bears 5 small spines, 3 of whichdiverge

upward

and

backward

^{and 1} projects freely ateach

1Seealso Starks,Ann.Carnegie. Mus.vol.7,1911, p. 195.

8FishesofNorthAmerica,p. 2076.

•Proc.U.S.Nat. Mus.,vol. 12, 1890, p. 91.

344

P-ROCEEDIXGS

OF THE NATIONAL MU8EVM.

vol.48.

lateral angle.

A

minute spine

may

^also be present in the

median

linedirectedforward.

The

dorsalfinisinsertednormallyonthe eighthplate ofthe dorsal series, but

may

occasionally vary to theextreme posterior edge of the seventh (pentacanthus), or the anterior edge of the ninth

(alascanus)

.

The

genus is perhaps nearer Bathyagonus than Xeneretmus, agreeingwith thelatterinthe characteroftherostral plate, andin the

number

of predorsal plates.

But

Bathyagonus is from deeper water, thewhole

body

andthefins areblackorbrownish black,the mandible is produced beyond the premaxillaries instead of being included within the latter, and the pectoral margin is entire

—

^the

lower rays not appreciably lengthened.

KeytospeciesofAsterotheca.

a}. Plateson cheeksthick, inflexible,immovablyunited with eachotherand with the interopercle. Lower5pectoral rays thickened.

A

^singlemedianpairof platesinfront of ventrals,theremainingplatesofmedianseriesunpaired(i.e., the platesofthesecondpairfused). Shallow waterspecies,with comparatively thick platesand heavyspinesandridges,andthelower partslightincolor.

6'.Marginofpreorbital not spinous. Ventrolateralseries ofplatessmooththrough- out,withoutspines; spines oflowerlateral series weakorobsolescent, this especiallymarkedon caudalpeduncle.

A

deep nuchaldepression. Space betweendorsal ridgesdeeplyconcave. Platesoncheeks, inadults,without spines or tubercles. Gill-menbranes withoutposterior freemargin. Lower pectoralraysmuchexsertedbeyondthemembrane,adistinctlydeeper notch between thetwoportionsofthefin. Nospineoninfraorbitalridgebelow

front ofeye alascana.

b^. Lower margin of preorbitalstrongly spinous in adults. Anterior plates of ventrolateralseries with short but evident spines;lowerlateral platesaU strongly spinous, exceptthe anterior 5or6, whichare smoothas inother species. Plates on cheeks with minute spines.

A

small spine on infra- orbitalridgebelowfront ofeye. Nuchaldepression shallow. Space between dorsal ridges shallowly concave. Gill-membranes withanarrowfreemargin posteriorly.Lowerpectoralrayscomparativelylittleexserted,no conspicuous notch betweenthetwoportionsofthefin infraspinata.

o^.Plateson cheeksthin, flexible, not fused,readily movable,all(ortheposterior two) bearingeacha strongbackwardlydirected spine. Ventrolateralseriesof plates sharply spinous throughout, as are the lower lateral series, with the exceptionofthefirst5or6. Twomedianpairsofplatesinfront ofventrals.

Lower4pectoralrays thickened, adeep notch betweenthetwoportionsofthe fin.

A

deeper waterspecies,with comparativelythinplates, lowridges,and delicatesharp spines; lower sideoftrunkandtaildarklikethe back;eye very large. Spines on eye-ball weak or obsolescent. Palatine patches of teeth

narrower thanthoseonmandible pentacantha.

ASTEROTHECAPENTACANTHA (Gilbert).

The

fin-raysin 18specimensvaryasfollows:

NO. 2075.

FISHES FROM SOUTHERN CALIFORNIA—

GILBERT.

345

Listofstations.

4306 4307 4258 4366 4410 4413 4421 4423 4510 4523 4533