Apodal Fishes of Bengal- 161 



II. — On the characters of Apodal Fishes. 



1. For want of a due regard to the proper characters by 

 which to distinguish the animals of this order, together 

 with the great uniformity in external shape which they 

 present, great inaccuracies are to be found in the notices 

 of naturalists regarding the identity and distribution of the 

 species. 



To obviate this, as well as to introduce more exactitude 

 into our views and observations regarding them, the follow- 

 ing remarks are brought together, as a summary of those 

 characters which appear to be of most utility in the prac- 

 tical examination and discrimination of these groups. 



In the order of fishes now under consideration, the ab- 

 dominal fins, corresponding with the lower extremities, are 

 wanting ; hence the name Apodal.* 



The absence of ventral or abdominal fins, is therefore an 

 essential character of the Order, although other fins are 

 frequently deficient in like manner. The pectoral fins are 

 also wanting in two-thirds of the known species, the caudal 

 fin is absent probably in one-tenth of the species ; and some 

 are without any fins whatever, unless we can allow a mere 

 fold of the skin, unsupported by fin-rays, to be such. 

 These membranous expansions are however, scarcely to be 

 regarded as fins strictly speaking, any more than the analo- 

 gous organs of the Manatus and other marine Mammalia, 

 in which instead of rays, we find all the bones proper to 

 limbs of quadrupeds. Indeed these finless fishes have 



* As the anterior extremities of other vertebrated animals are represented in 

 fishes by the pectoral fins, so the posterior extremities are represented by the ven- 

 trals. The functions of the posterior extremities are subject to fewer modifications 

 than the anterior which, serve as hands, feet, or wings, according to the order of 

 nature to which the animal belongs. Throughout the whole of the vertebrata, with 

 the exception of fishes and marine mammalia, the functions of the posterior extre- 

 mities are the same. Hence we have one reason for coinciding with Mr. MacLeay, 

 in regarding fishes as the most imperfect of vertebrata. Vid. vol. II. p. 263. 



