GONOSTOMATIDAE 301 



Described from 10 specimens, the largest 25 mm. in length. 



Hab. Between Greenland and Iceland; Atlantic; Madagascar; Indian Ocean; Timor 

 Sea; coast of California. 



Family STERNOPTYCHIIDAE 

 Genus Argyropelecus, Cocco, 1829 

 Synopsis of the Species of Argyropelecus 



I. Photophores forming a nearly continuous series. 



A. Depth of body (without dorsal ridge) 2 J to 2| in the length ; praedorsal ridge rather low, 

 length of exposed portion of last spine more than twice in the base of the dorsal fin. 



I. affinis, Garman, 1899 



B. Depth of body (without dorsal ridge) i| to nearly 2 in the length; praedorsal ridge higher, 

 length of exposed portion of last spine 1 1 to i § in the base of the dorsal fin. 2. gigas, n.sp. 



II. Postabdominal photophores in three groups (prae-anal, supra-anal, and caudal). 



A. A single serrated abdominal spine ; supra-anal photophores separated from prae-anals by a 

 distance of more than half the length of the supra-anal series, and from the caudal by a 

 distance which is greater than the length of the supra-anal series. 



3. hemigymtius, Cocco, 1829 



B. A pair of smooth abdominal spines ; supra-anal photophores separated from the prae-anals 

 by a very short interspace, and from the caudals by a distance which is less than the length 

 of the supra-anal series. 



1. Posterior abdominal spine longer than the anterior and directed backwards; adults with 

 the dorsal and abdominal ridges serrated, and with a double series of spines on the lower 

 edge of the caudal peduncle. 4. acideatiis, Cuv. and Val, 1850 



2. Abdominal spines subequal or anterior the longer; dorsal and abdominal ridges not 

 serrated ; no spines on the caudal peduncle. 



a. Lower praeopercular spine curved, the upper very small or absent ; depth of body 

 about il in the length. 5. olfersii (Cuvier, 1829) 



b. Lower praeopercular spine straight, the upper of moderate size or rather small, 

 directed backwards; depth of body if or more in the length. 



6. sladeni, Regan, 1908 



Argyropelecus elongatus, Esmark [1871, Fork. Vid. Selsk. Christiama (1870), p. 489], 

 is too briefly described to be identified with certainty, but may be synonymous with 

 A. affinis. A. bocagei, Osorio [1909, Mem. Mas. Bocage, i, p. 27, pi. ii, fig. 3], is also 

 unrecognisable. 



Argyropelecus affinis, Garman. 



Argyropelecus hemigymnus (non Cocco), Goode and Bean, 1895, Ocean. Iclith. pi. xxxix, fig. 147. 

 Argyropelecus affinis, Garman, 1899, Mem. Mus. Comp. Zool. xxiv, p. 237; Brauer, 1906, 

 'Valdivia' Tiefsee-Fische, p. 103, pi. vii, figs. 1-2; Regan, 1908, Trans. Linn. Soc. Zool. xu, 

 p. 218 ; Jespersen and Taning, 1915, Rep. Danish Ocean. Exped. 1908-10, 11, A, 2, p. 6; Barnard, 

 1925, Ann. S. Afric. Mus. xxi, p. 152, pi. viii, fig. i. 

 St. 296. 26. viii. 27. 8° 12' 00" N, 18° 49' 00" W. Young-fish trawl, 450-500 (-0) m. : 2 speci- 

 mens, 43-55 mm. 



Hab. Atlantic; Caribbean Sea; Indian Ocean. 



