1909.] R. E. lyi^OYD : Deep-Sen Fish caught hy the '' Investigator:' 145 



Consistency and general appearance distinctly bathybial. Colour dark brown 

 above, greyish brown below. 



Habitat.— Gulf of Aden ; 130 fathoms. Station 360. Registered Nos. F u^f--^. 



Benthobatis moresbyi, Alcock. 



Ann. Mag. Nat. Hist, (y), vol. v, p. 145 (1898) ; Cat. Indian Deep-Sea Fish, p. 18 



(Calcutta, 1899); Illustr. Zool. ''Investigator," Fishes, pi. xxvi (1899). 



One small specimen from 585 fathoms, off the south coast of Arabia. Station 

 358. Registered No. F ^^i^. 



Order TELEOSTEI. 



Suborder Malaco.pterygii, 



Family ALEPOCEPHALID^. 



Genus Pi^atytroctegen, nov. 



Resembling the genus Platytroctes (Günther) , but differing from it in possessing 

 small but well-developed pelvic fins. The deep folds of skin which in Platytroctes 

 form the dorsal and ventral contours of the body are not empty as in that genus but 

 are occupied by a thick layer of connective tissue. The scales are not keeled. 



Platytroctegen mir us, sp. nov. 

 B. 6, D. 23, A. 23, P. 28, V. 5. 



The greatest depth of the body is one-third of the total length without the cau- 

 dal. The length of the head is slightly more than a quarter of the total without the 

 caudal. The diameter of the eye is slightly less than one- third the length of the 

 head. The length of the snout is equal to half the diameter of the eye. 



Minute teeth occur in a single row on the premaxillaries, maxillaries and den- 

 taries ; there are a few small teeth on the vomer. The palatines are toothless. 



The innermost of the four gills is half the length of the others. Filaments and 

 rakers are about a third of the diameter of the eye, the gill-rakers of the first arch are 

 longer than the others. 



A small tubular papilla with an apical pore rises from the skin a short distance 

 behind the operculum on a level with the centre of the eye. 



The upper surface of the head, which is triangular and nearly flat, is bounded on 

 either side by straight supraorbital ridges, converging in front. The supraorbital 

 ridge, the infraorbital and pre-opercular bones each support a muciferous canal open- 

 ing at intervals. 



The lower ends of the clavicles, which together form a remarkable bony spine, 

 are in contact up to their apices. 



The gill-cover of the left side overlaps that of the right side at its lower end, 

 where it contains an extra or seventh small branchiostegal ray, not represented on 

 the right side. 



