338 CLASSIFICATION OF FISHES. 



(279») ^Ve are thus brought back again to the point 

 from whence we started ; and we find that the genera of 

 the Loricaria describe a circle, whose analogies may be 

 thus expressed : — 



Genera of the An,>„i n „- Sub-families of 



Loricarixj. Analogies. the SltURIDi . 



Loricaria. [ ^neath'^ ^^ """^ plaCed }LoRicARi.N:F„ 

 Hypostoma. {^^os™ ***** ^ ^ SeC ° nd } Pi^elodixx. 



Hoplisoma. } T ^^" agi Vent ° l0Se t0 the peC " ] Stanmut 



Cataphractus. Eyes very small, nearly vertical Aspredin\e. 



Siurisama. Snout lengthened, depressed. Sorvbixje. 



The representation which these genera of the Lo- 

 rlcarince gives us of the primary divisions of the 

 whole family, developes their analogy, likewise, with 

 the primary orders of fishes. It is, indeed, a most in- 

 teresting circumstance to find that in such a group as 

 this we should have a representation of the Gymnetes, or 

 riband-fish, in the compressed shape of ffoplisoma, so 

 totally at variance with all the other genera ; while the 

 small vertical eyes, and the general aspect of Cata- 

 phractttSj remind us immediately of Aspredo. 



(280.) The sub-family of the Pimelodix^e is dis- 

 tinguished by positive and negative characters, or, rather, 

 of two which are universal, and of two which admit of 

 some partial exceptions. The mouth, in the first place, 

 is always terminal: the body, likewise, is naked; 

 for although, in consequence of their close affinity to 

 the LoricariruB, some few of these fishes have a 

 single row of small plates upon their sides, and even 

 on their head, yet these plates never extend beyond 

 the nape. They have all two dorsal fins ; the hinder 

 being completely adipose, or without any vestige 

 of rays. Their more striking peculiarity, as already 

 remarked, is in the length of the belly and tail being 

 equal, so that the anal fin is never of that exceeding 

 length which it is in all the Silurinte. Some idea of 

 the numerous modifications of form that enter into this 

 group, may be gathered by looking to the contents 



