GONOSTOMATIDAE 297 



A single species. 



This aberrant genus appears to be most nearly related to Vincigiierria, and the 

 manner in which the photophores develop seems to be the same. Jespersen and Taning, 

 who have described the marked metamorphosis undergone by Ichthyococciis, state that 

 in Vincigiierria attenuata (but not in any other species of that genus) the eye is somewhat 

 telescopic in the adolescent stages, but that this character is scarcely apparent in the 

 adult. In the telescopic eyes, narrow interorbital region, etc., Ichthyococciis approaches 

 the Sternoptychiidae, but is essentially Gonostomatid in general structure. 



Ichthyococcus ovatus (Cocco). 



Gonostomus ovatus, Cocco, 1838, A^. Ann. Sci. Nat. 11, p. 169, pi. i, fig. 3. 



Ichthyococcus ovatus, Bonaparte, 1841, Icon. F. ItaL (27), Indice [4] and (138**) [2]; Vaillant, 



1888, Exped. Sci. ^ Travailleur' et ' ToUsman', Poissons, p. 104, pi. xiv, fig. 2; Moreau, 1891, 



Hist. Nat. Poiss. France, Suppl. p. iii ; Goode and Bean, 1895, Ocean. Ichth. p. 95, fig. 113; 



Brauer, 1906, ' Valdivia' Tiefsee-Fischc, p. 94, figs. 38-39; Zugmayer, 191 1, Res. Camp. Sci. 



Monaco, XXXV, p. 57 ; Sanzo, 1913, Mem. R. Com. Talass. Ital. xxvn, fig. ; Jespersen and Taning, 



1919, Vid. Medd. Dansk nat. For. Lxx, p. 218; 1926, Rep. Danish Ocean. Exped. 1908-10, n, 



A, 12, p. 38, figs. 



Scopelus ovatus, Cuvier and Valenciennes, 1849, Hist. Nat. Poiss. xxn, p. 453. 



Coccia ovata, Giinther, 1864, Cat. Fish, v, p. 388; Carus, 1889-93, Prodr. F. Medit. n, p. 568. 



Depth of body 2\ to af in the length, length of head nearly 3. Snout shorter than eye, 

 diameter of which is 2f to 3 in length of head. About 15 gill-rakers on lower part of 

 anterior arch. 36-39 scales in a longitudinal series. Dorsal 11-12; origin about equi- 

 distant from end of snout and base of caudal. Anal 15-17. Pectoral with 8 rays. Pelvic 

 with 7 rays. Lower series of photophores consisting of 25 (7 + i + 17) in front of 

 pelvic, 10 or II from pelvic to origin of anal, and 13 or 14 from anal to base of caudal; 

 there are 23-26 photophores in the upper series. 



Described from 16 specimens, 25 to 44 mm. in length. 



Hob. Mediterranean; Eastern Atlantic; Indian Ocean. 



Genus Maurolicus, Cocco 



Cocco, 1838, N. Ann. Sci. Nat. u, p. 192. 



Triarcus, Waite, 1910, Trans. N. Zealand Inst. XLii (1909), p. 387. 



Two species. 



Cleft of mouth wide, rather oblique, the lower jaw a little projecting; both jaws with 

 a single series of minute teeth ; a single transverse row of similar teeth on the head of 

 the vomer. Pseudobranchiae well developed ; gill-openings very wide ; gill-rakers long, 

 slender, fairly numerous. Scales present. Photophores large and conspicuous; lower 

 series on body more or less broken up into groups ; the series between pelvic and origin 

 of anal separated from that above anterior part of anal. Dorsal 9-12; origin nearer to 

 base of caudal than end of snout. A long, low, adipose fin. Anal 23-27 ; origin just behind 

 last dorsal ray. 



Two species. 



