74 -A Guide to the Zoological Collections 



(2) Bathytroctes, which also occurs in the Atlantic : 

 two species live in Indian seas, at 500 to 740 fathoms : 



(3) Narcetes, which differs from the two previous 

 genera only in dentition : 



(4) Platytroctes, which has a curious high, compressed, 

 body, and no ventral fins: the same species P. apus 

 occurs in the Atlantic and in these seas : 



(5) XenodermichthySy which occurs in the Atlantic and 

 in these seas at considerable depths : it has a black 

 scaleless skin, with minute luminous organs, and a 

 large eye : 



(6) Leptoderma, which also occurs in the Atlantic : it 

 has a black scaleless skin with a luminous epidermis, 

 and an eye of enormous size. 



(7 j Aulastomomorpha, which has the bones of the head 

 produced to form a tube-like snout, and the skin of the 

 head brilliantly phosphorescent. 



Family XI. Notojrteridce [Cases 68-69]. 



This small family contains a single genus (Notoptcrus) 

 of fishes that inhabit freshwater of the Oriental and 

 West African regions. They are related to the Her- 

 rings. The two Indian species are known in Bengal as 

 Chitala and Phola. 



Family XII. Halosauridce [Case 72]. 



This is a small family containing one genus, Halo- 

 saurus, the species of which are found only in the depths 

 of the Oceans. Five species occur in the seas of India, 

 at depths of 500 to 1000 fathoms. They have a long 

 tapering eel-like body, covered with scales, and in many 

 of the species the scales of the lateral line are enlarged 

 and grooved or perforated to lodge a luminous organ, 



