278 gangetic fishes. Order V. 



thirteen rays in the fin of the back ; and with seven in that be- 

 hind the vent. 



The Dero [Dhengro) I found in the Brahmaputra river. It 

 has the colours and form of the fishes of the seventh division, 

 to be afterwards mentioned, but, on account of the ridge on the 

 lower jaw, must certainly be placed here. It seldom exceeds 

 four inches in length. The colours of the back and belly are ir- 

 regularly indented into each other on the sides. The dorsal and 

 caudal fins are dotted. 



The head is oval and blunt. The nose projects a little be- 

 yond the mouth, and is fleshy, and marked with callous points. 

 At each corner of the mouth is a minute tendril. The mouth 

 is small, the upper jaw protruding in opening. The lips are 

 fleshy, and smooth on the edges. The nostrils are in the mid- 

 dle, between the eyes and point of the nose. The eyes are high 

 up, and small, and have circular pupils. The gill-covers are al- 

 most naked. 



The back slopes gently before the fin, and is rather sharp- 

 edged. The edge of the belly is rounded. The lateral line is 

 below the middle, and is bent downward. The scales are of a 

 moderate size, and those on the back have some dots. 



The second ray of the bach fin is longer than the first, and 

 shorter than the third, — all the three being undivided, and de- 

 void of joints ; the others are branched. The 'pectoral fins are 

 shorter than the head, and each contains about eighteen rays.- 

 The ventral fins reach to the vent, and are small. The fin be- 

 hind the vent slopes backward, and its first ray is short, and 

 closely united to the second, both being undivided, while the 

 others are branched ; and the last is divided to the root. The 

 lobes of the tail fin are sharp and equal, and contain nineteen 

 distinct rays, besides several short compacted ones. 



