INDIAN FRESH - WATER FISHES. 
1 04 
I will next take into consideration the large and 
important 
ORDER ACANTHOPTERYGII, 
or spiny rayed fishes. 
In most systematic works this order is placed first, 
it does not, however, occupy such an important place 
among the Indian fresh- water fishes as it does in 
other parts of the world, and for this reason I have 
placed them after the Physostomi. 
They are to be distinguished by having a number 
of the rays of the dorsal and anal fins and often the 
first ray of the ventral composed of strong sharp 
spines. They have frequently two dorsal fins, but 
both of them are composed of rays, and the adipose, 
or gristly, fin does not appear in this order. When 
fhere are two dorsal fins, the first is composed 
entirely of spinous rays, or the two fins may be 
united. The Ophiocephalkke appear at first sight to 
be exceptions to the general rule, inasmuch as they 
have no spinous rays in any of their fins. There is 
no doubt, however, of their belonging to this order, 
and we may conclude, as occurs in some other cases, 
that the first dorsal fin is wanting, or perhaps on 
account of their burrowing habits, the soft portions of 
their fins may have become developed at the expense 
of the spiny rays. 
