DISCUSSION OF SPECIES AND THEIR DI8TRIBIlTrON. 123 



Giinther described this seims and s|)ecies liom a siieciineu .".A inches h)iii;-, o1)taiiied 

 south of the Philippine Islands, at VhaUnKjcr Station ccxiv, at a depth of 500 fatlionis. He 

 had previously obtained, in 1808, the speciuKui collected by Lowe at Magdalena. The 

 Albatross obtained a single specimen from station 2392, in L>8o47'30" IS. lat., 870 27' W. 

 Ion., at a depth of 724 fathoms. 



The capacity of this form for swallowing fishes greater in size than itself appears to be 

 as great as that of Chiasmodus, as may be understood ft-om au inspection of ligure c' in 

 Giinther. 



Family STERNOPTYCHIDyE. 



Sterno2>tychida:, Guntiier, Cat. Fish. Brit. Mus., v, 1864, 384, (part group Slernoplycliina). — Gin,, Arr. Fami- 

 lies Fishes, 1872, 15 (Family No. 153, name only) ; Proc. U. S. N. M., vil, 1881, 350 — Jorhan and 

 Gilbert, BuU. xvi, U. S. Nat. Mus., 283. — Jordan, Cat. Fish. N. Am., 46. 



Malacopterygians with compressed ventradiform body, carinated contour, deeitly and 

 obliquely cleft and subvertical mouths, whose upper margin is constituted by the supramax- 

 lUaries as well as the intermaxillaries ; brauchiostegal arch near and parallel with lower 

 jaw, scapular « ith an inferior projection, and with one or more of the neural spines abnor- 

 mally developed, and projecting above the back in advance of the dorsal fin. (Gill.) 



KEY TO THE GENERA AND SPECIES. 



I. Body naked. 



Abdominal outline nearly continuous in a sigmoid curve, a single produced spike-like neural spine in front 



of the dorsal fin, and about 5 branehiostegal rays Sterxoptycuin.e, Gill 



A. Teeth in the jaws in several series; dorsal fin with spinous dilatations Sternoptyx 



1. Height of body equal to length, without caudal Sternoptyx m.\PHANA 



Abdominal outline abruptly contracted in advance of anal, several produced neural spines constituting 

 a uniform edge in advance of dorsal, and about 9 branqhiostogal rays Augyropelecin.e, Gill 



A. Teeth in the jaws in a single series, minute Argyropelecus 



1. Tail spineless. 



a. Mandible with flat spine at its lower .angle. 



i. Pectoral fin extending nearly to origin of anal A. hemigy'MNUS 



ii. Pectoral extending to ventral A. Oi.fersii 



b. Mandible without spine A. D'Urvillii 



2. Double row of spines along side of tail A. acui-e.^tus 



B. Teeth in jaws long and recurved Ster.xoptyciiides 



II. Body covered with large, thin, deciduous scales. Anterior spinous dilatation of dorsal flu lacking. 



POLY'irMNJi 



A. Luminous organs much developed Polyipnus 



STERNOPTYX, Herm.\nn. 



Sternoptyx, Hermann, Naturforscher, xvi, 1781-2.— Covier and Valenciennes, Hist. Nat. Poiss., xxii, 412.— 

 GttNTHER, Cat. Fish. Brit. Mus., v, 386; Challenger Report, xxii, 16!t, pi. XLV, figs. D, D'. 



Body much elevated and compressed, passing abruptly into a, short and compressed 

 tail, the angle made by the hind margin of the trunk and the lower edge of the tail being 

 filled up by a broad fold of tlie integument, of peculiar trans])arent appearance, resembling 

 thin cartilage. This fold bears the anal fin and is supported l)y interha-mal rays. The 

 greater portion of the l)ody is scaleless and covered with a silvery pigment. A series of 

 luminous spots runs along the losver edge of the abdomen and is separated from that of the 

 other side by a cartilaginous fold occupying the median line of tiie abdomen: another series 

 runs on each side of the isthmus; a row of three above and behiml the root of the ventrals, 

 and another row of three above the vent. The luminous organs on the lower part of the 

 tail consist anteriorly of a row of four, of which the first is prolonged along the back as a 

 narrow band, terminating about the middle of tlie depth of tliebody in a globular black 

 spot with a white center j posteriorly in front of the caudal rays there is another row of four 

 small spots. 



