18 



Tail very distinct from the oval disk and vrithout distinct lateral folds. Two 

 dorsal fins on the tail ; caudal fin well developed. 



Nasal valves confluent into a quadrangular curtain. 



Teeth flat, rhomboidal, with the posterior angle acutely produced. 



Spiracles large, situated immediately behind the inconspicuous and quite 

 rudimentary eyes. 



A large electric organ between the head and either pectoral fin. 



This curious blind torpedo differs from all other members of the family in 

 having the eyes quite rudimentary and in the absence of lateral folds of skin on 

 the tail. In general form it resembles Narcine, though the disk is not quite so 

 broad. The teeth, like those of Discopyge, have the posterior angle produced, 

 but more acutely than in Discopyge, judging from Tschudi's figure. 



6. Benthobatis Moresbyi, Alcock. 



Benthobatis Moresbyi, Alcock, Ann. Mag. Nat. Hiet. August, 1898, p. 145 : Illustrations of the Zoology of 

 the Investigator, Fishes, pl. XXVI. fig. 1. 



The disk is oval, its long axis, which is fore and aft, is a little shorter than 

 the tail : more than a third of its extent is pre-oral. 



The eyes are represented by two small unpigmented spots, each not much 

 bigger than the head of a pin, situated one in front of either spiracle ; a slender 

 optic nerve passes to each, and expands into a vesicle so small as to need a lens 

 for its recognition. 



The mouth is small and protractile ; the teeth are small rhomboidal plates, 

 with the posterior angle strongly and acutely produced, and are arranged in 

 mosaic in about ten very oblique series in either jaw. 



The gill-openings are large and well-spaced : the posterior one is nearer to 

 the cloacal opening than to the mouth. 



The dorsal fins are placed rather close together, the first being a little in 

 front of the posterior limit of the ventrals, and, like the caudal, are thick and 

 fleshy. The ventrals are of the usual shape ; though they are separate, the skin 

 between them is loose and copious. The whole animal is covered with a per- 

 fectly smooth, soft, glandular, purplish-black skin ; scattered on the disk and 

 round the edge of it are some small white pores, not much smaller than the 

 eyes ; in one specimen part of the tips of the second dorsal and caudal fins are 

 white. 



Two males (each about 14- inches long) and a young one, from off the 

 Travancore coast, 430 fath. 



-r, -■ AT 232 234 



Regd. JNos. -j- : — . 



