THE SILURID-ffi IN GENERAL. 32? 



except under a high magnifier : hence we may safely 

 infer, that the major part of the Siluridce swallow their 

 food entire ; and that, as the mouth is moderate, the 

 fishes they capture must be of a small size. It is more 

 than probable, also, that several of them feed as much 

 upon vegetable as upon animal substances ; something 

 in the manner of carp and eels. The worm-like and 

 flexible cirri, or barbels, of the Siluridce, as before ob- 

 served, is another of their most remarkable distinctions: 

 those on the upper lip are always the most developed, 

 and among the Pimelodince are often as long as the 

 whole body : these are supported by the intermaxillary 

 bones ; and, from their great length, command a much 

 wider range than those on the under lip, which are 

 usually shorter. The head is exceedingly depressed, 

 being often almost flat ; so that its height, when viewed 

 in profile, is not more than one fourth, and even less, 

 of the vertical breadth : the mouth is small or moderate, 

 and the eyes by no means equal to those of the generality 

 of fishes. The body is always destitute of true scales, 

 even of those obsolete ones seen in the neighbouring 

 group of the Gadidce, or cods ; yet, if naked, it is very 

 slimy ; and in the typical group, or the Loricarince, the 

 whole head, and the greater part of the body, is mailed 

 by hard bony plates, which makes them appear like the 

 mailed ant-eaters of India, and apt representatives of 

 the chelonian reptiles and the loricated fishes. The 

 Siluridce, as we have already shown, are the most 

 aberrant of all the soft-finned order : this at once ac- 

 counts for the fact, that the great majority of the species 

 have the first ray, both of their dorsal and their pec- 

 toral fins, not only spined, but usually very thick ; and 

 these rays are rendered sometimes more formidable, as 

 weapons of defence, by having one or both edges finely 

 toothed, with the points directed inward. Dr. Bu- 

 channan Hamilton, in reference to this peculiarity of the 

 cat-fish, conjectures that, " in general, every time that 

 they are employed, the animal must suffer considerably, 

 as, in most of the species, these prickles terminate in a 



y 4 



