CoiuS. GANGETIC FISHES. 89 



branch of the second ray in each ventral fin produced into a 

 bristle. 



Some fishermen reckon this a species of Coius, others call it 

 a Vacti, and it has no doubt a considerable affinity to the last 

 described species. Others, however, consider it as forming a 

 distinct genus, and I have adopted the name which these give 

 it. The Calamara of Russell (Indian Fishes, Vol. I. No. 92) 

 has a very great affinity to our Datnia ; but has a thicker body, 

 and wants the bristle-like elongations in the ventral fins, and 

 the spot on the fin behind the vent. 



This is a very beautiful fish, from six to ten inches in 

 length. It is found in all the mouths of the Ganges, and is 

 common in the Calcutta market ; but is not near so good for 

 eating as the vacti. 



The datnia, in proportion to its length, is a thick fish, and its 

 general colour is silver, with faint interrupted longitudinal 

 stripes, which above are green, with a gloss of gold, and below 

 pearly. The first back fin is edged, and the second and tail 

 fin are stained with black. On the fin behind the vent there 

 is a large irregular black spot. 



The head and back descend in the segment of a circle. The 

 former is oval, somewhat sharp, of a moderate size, and cover- 

 ed with scales to the eyes, before which it is naked. The mouth 

 is of a moderate size and terminal, and passes almost directly 

 backward. The under jaw is rather the shorter. The bones of 

 the upper lip are minute. The anterior teeth in both jaws are 

 sharp, conical, of unequal size, and placed in a single row : the 

 posterior ones are blunt and crowded together. The tongue is 

 sharp, and slightly tied down. The palate is smooth, and, be- 

 hind the teeth, has a short membranous veil. The posterior 

 aperture of each nostril is oblong ; the anterior is provided with 

 a short tube. The eyes are rather large. Each gill-cover con- 



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