580 FISHES. 



SiSOR. — Head depressed, spatulate ; trunk depressed ; tail 

 long and thin. One short dorsal fin ; anal short ; ventrals 

 seven-rayed. Head partially osseous, rough ; a series of bony 

 plates along the median line of the back ; lateral line rough. 

 Eyes very small. Mouth inferior, small, transverse, with bar- 

 bels ; teeth none. 



A single species, *S'. rhahdopliorus, from rivers of northern 

 Bengal. Allied to this genus is Ercthistes from Assam. 



PSEUDECHENEis. — Adipose fin of moderate length ; a short 

 dorsal with one spine and six rays ; anal fin rather short. Bar- 

 bels eight. Mouth small, inferior. Head depressed, covered 

 with soft skin above ; eyes small, superior. Caudal fin forked ; 

 pectorals horizontal, with a thoracic adhesive apparatus between, 

 formed by transverse plaits of the skin. Ventrals six-rayed. 



A very small species, inhabiting the mountain-streams 

 of Khassya ; by means of the adhesive apparatus it is enabled 

 to hold on to stones, tlins preventing the current from sweep- 

 ing it away. Ejiostoma is a similar small Siluroid from Indian 

 mountain-streams, but without the thoracic apparatus ; pro- 

 bably its mouth performs the same function. 



I. ASPREDININA. 



AsPREDO. — Adipose fin none ; dorsal short, without pungent 

 spine ; anal very long, but not united with the caudal. Head 

 broad, much depressed ; tail very long and slender. Barbels 

 not less than six, one of which is attached to each intermaxillary ^ 

 none at the nostrils. Eyes very small. Head covered with soft 

 skin ; the anterior and posterior nostrils are remote from each 

 other. Ventrals six-rayed. 



Six species are known from Guyana ; the largest grows to 

 a length of al30ut eighteen inches. The remarkable mode of 

 taking care of their ova has been noticed above (p. 161, Fig. 

 72). Bunoccphalus, Bmiocephaliclithys, and Harttia, from 

 tropical America, are other genera of this sub-family which 

 remain to be mentioned. 



