I860.] The Cartilaginous Fishes of Lower Bengal. 41 



Pastinaca hrevicauda, Swainson, founded on Russell's fig. V ; but in 

 this figure the tail is represented as being still shorter than in Tr. 

 walga. The larger of two specimens (a female) measures 3^ in. 

 to base of tail, the tail 6 in. ; the latter being broad at the base, and 

 very rapidly attenuating from base of spine, which last is 1\ in. long. 

 These specimens have much the appearance of being the young of 

 some considerably larger species ; but the shortness of the tail separates 

 it from any of the following.* 



The remainder have exceedingly long tails, from three to four times 

 the length of the head and body. All have at least one large bony 

 tubercle in the centre of the dorsal surface. At least five species are 

 brought more or less commonly to the Calcutta fish-bazars, which 

 are easily distinguished at any age, though supposed by Dr. Cantor 

 and others to be merely varieties, or characteristic of different ages, 

 of Tr. uarnak, (Forsk.) 



19. Tr. Bleekeki, nobis, n. s. A large species, plain dark brown 

 above and below with a narrowish white median patch on belly. 

 Peak, or anterior junction of pectorals, considerably more prolonged 

 and pointed than in the others. Medial third of dorsal surface 

 studded with intermixed larger and smaller round flat tubercles, con- 

 tinued along the upper surface of the tail as far as the caudal spines, 

 then thickly covering the whole tail to its extremity in adults, or 

 with a naked line below in specimens more than half-grown. Along 

 the median line of the tail above, the tubercles are not larger than 

 the rest. The usual large round tubercle on centre of back, and 

 commonly three smaller, set in form of a triangle, before it and three 

 similar behind it. In all that I have seen the caudal spine had been 

 broken or entirely torn out by the fishermen. Length of one 25 in. 

 to base of tail, the tail 72 in. ; of another 15 and 56 in. 



20. Tr. Ellioti, nobis, n. s. Pale greyish olive-brown above and 

 white below : the united pectorals not more prolonged in front than in 

 Tr. tjarnak. Size of last ; at least I have obtained one tail 6 ft. in 

 length, but the fish was cut into small slices. A young individual 

 8| in. long to base of tail, 9£ in. broad, with tail 29 in., has a central 



* Dr. Bleeker gives the breadth of fivo specimens (four of them females) as 

 140 to 190 mill. 



