[45] 



CATALOGUE OF THE FISHES OF NORTH AMERICA. 



Family LI.— STERNOPTYCHID^.i (43) 



146.— ARGYROPELECUS - Cocco. 



533. Argyropelecus bemigymnus Cocco. O. Eu. 



534. Argyropelecus olfersi Cuvier. O. Eu. 



147.-STERNOPTYX» Hermann. 



535. Stemoptyx diaphana Hermaun. O. Eii. 



1 A 8iil)order Iniomi, to include tbe Sternoplychida', and Chauliodontidm, has been pro- 

 posed by Dr. Gill, Proc. U. S. Nat. Mus., Idd4, 350. The chief respect iu which these 

 fauiilics differ from the other Isospondyli is in the mode of articulation of the scapular 

 arches, which counect with and impinge ou the occiput behind and are otherwise 

 free from the cranium, ijviov, nape; a3/<(5?, shoulder.) 



Dr. Giinther and others have stated that the Siernoptychidce possess a "rudimentary 

 epiuous dorsal fin." This appearance is due to the projection of one or more of the 

 neural spines beyond the muscles, and is in no proper sense a rudiment of a fin. (See 

 Gill, I.e., 350.) 



2 Argyropelecus Cocco. 



{Pleurothyris Lowe.) 



(Cocco, Giorn. Sci. Sicil., 1829, fasc. 77, p. 14G; type, Argyropelecus hemigymnns 

 Cocco.) 



Body much elevated anil compressed, passing abruptly into the slender tail ; no 

 scales, the skin covered Avith silvery pigment; series of phosi)hore8ceut spots along 

 the lower side of the head, body, and tail. Head large, compressed, and elevated, 

 the bones thin but ossified. Cleft of mouth wide, vertical, the lower jaw jirominent. 

 Margin of upper jaw formed by the maxillary and premaxillary, both of which have 

 a sharp edge, which is beset with minute teeth; lower jaw and palatine bones with 

 a series of small curved teeth. Eyes large, very close together, lateral, but directed 

 upwards. Angle of preopercle with a spine usually directed downwards. Pectorals 

 w ell developed ; veutrals very small. Humeral arch and jjubic bones prolonged into 

 flat pointed jirocesses, which project in the median line of the belly; a series of im- 

 bricated scales from the humeral bone to the pubic spine, forming a ventral serrature. 

 Dorsal fin short, metliau, preceded by a serrated osseous ridge, consisting of several 

 neural sj)iue8 prolonged beyond the muscles. Adipose fin rudimentary ; anal fin 

 short ; caudal forked. Gill opening very short, the outer branchial arch extending 

 forward to behind the symphysis of the lower jaw, and beset with very long gill 

 rakers; branchiostegals nine; pseudobranchiie and air-bladder present. Four pyloric 

 ccKca. Small pelagic fishes. (-4/3;'i'/30?, silvery ; TtaXsHvi, hatchet.) 



Argijropelecus hemigymnns Cocco. Depth of body equal to distance between gill- 

 opcniugs and base of caudal; posterior corner of mandible and angle of preopercle 

 ■each with a small triangular. spine; tail without spines; pectoral fin nearly reaching 

 anal. B. 9, D. 7 or 8, A. 11, P. 9, V. 5, L. 2 inches, (Giinther). Atlantic and Mediter- 

 ranean in deep water; not rare in the Gulf Stream ofl:" Southern New England. 



(Cocco, 1. c, Cuv. & Val. XXII, 398; Gunther, V, 3%; Goode & Bean, Bull. Mus. 

 Comp. Zool., 1882, 220.) 



Argyropelecus olferai (Cuvier) C. & V. Depth nearly or quite equal to distance 

 from shoulder to root of caudal ; tail as deep at base as long. Mandible with a short 

 flat spine at its posterior corner; preopercular spine directed downwards; tail with- 

 out spines; pectoral fin reaching ventrals. B. 9, D. 9, A. 11, P. 10, V. 6 (Giinther). 

 Coast of Norway, lately taken in the Gulf Stream, off Southern New England. 



(Sienioptyx olfersi Cuvier, Eegne Animal., ed. 2d, II, 316; Cuv. & Val. XXII, 408; 

 Giiuther, V, 386; Pleurothyris olfersi Lowe, Fish. Madeira, 64.) 



^Sternoptyx Hermann. 



(Hermaun, Naturforscher, 1771, XVI, 8 ; type Sternoptyx diaphana Hermann.) 



Trunk much elevated and compressed, the slender tail very short; abdominal out- 



