1871.] FRESHWATER SILUROIDS OF INDIA. 715 



Head as broad as long, depressed, covered with skin. Snout 

 broad. Caudal peduncle two thirds as high as long. Thoracic ad- 

 hesive apparatus small. Gill-membranes generic. Lips not fringed. 

 Maxillary barbels with broad bases, and nearly as long as the head, 

 the nasal reaching halfway to the orbit, the external mandibular 

 pair longer than the internal. Occipital process slightly longer than 

 it is broad at its base. 



Fins. Dorsal nearly as high as the body, its spine half as long as 

 the head and enveloped in skin ; adipose dorsal rather low, its base 

 slightly longer than that of the first dorsal. Pectoral spine broad, 

 reaching two thirds of the distance to the base of the ventral, not 

 plaited inferiorly, whilst externally it is smooth, and internally has 

 seven strong denticulations ; it is two thirds as long as the head. 

 Caudal forked, lower lobe slightly the longer. 



Skin smooth. Air-vessel generic. 



Colours. Uniform brown. 



Hab. Numerous specimens up to 3 inches long from the upper 

 portion of the Jumna. 



Geographical distribution. — Throughout India (? Madras), Bur- 

 mah, to the Malay archipelago. Some species when small appear 

 to be found in mountain-streams. 



Genus Exostoma, Blyth. 



Air-vessel in a globular form on either side of the body of the 

 anterior vertebrae, and enclosed in bone. 



Exostoma blythii, Day, Proc. Zool. Soc. 18G9, p. 525. 



D. \\0. P. i V. 6. A. f. C. 13. 



An erratum occurred in the original description in the number of 

 anal rays, which are seven, the two first of which are undivided. 



Having been favoured by Mr. Mundali and Dr. Stoliczka with 

 several specimens up to 3^ inches in length, I find its habitat to be 

 the rivers below Darjeeling. 



In some of the larger specimens the caudal fin is not lobed, but 

 its outer rays are rather elongated, whilst all the intermediate ones 

 are of the same length. 



Geographical distribution. — This genus, so far as I have been 

 enabled to trace its species, commences in the rivers below Darjee- 

 ling (E. blythii) ; it is then found in the Mishnee mountains in 

 Assam (E. labiatuin) ; more to the east it has its representatives in 

 Tenasserim (E. berdmorei) ; whilst specimens were brought by the 

 expedition which went through Upper Burmah to China (E. a'nder- 

 sonii). 



The systematic arrangement of the family Siluridee has always 

 been found intricate, judging from the constant changes to which it 

 has been subjected. Although I have no new system to propose, I 

 would draw attention to some points respecting those genera which 

 inhabit the waters of India, which seem to show that further altera- 



