286 



CLASS REPTILIA. 



sake of convenience, into two distinct families. The one has 

 the skin naked, or equally scaly underneath. These are 

 called HoMODERMATA. The other has the skin covered 

 above with small scales, and below with large corneous 

 plates. This is the family called Heterodermata. The 

 first are harmless, and of small size in general, and feed on 

 insects, and other very small animals. Among the second 

 are many venomous species, and many of very formidable 

 dimensions. 



A superficial examination is sufficient, generally speaking, 

 for the purpose of immediately distinguishing an ophidian 

 from every other reptile. Nevertheless, there are some of 

 them in which, without a certain degree of attention, relations 

 might be discovered to species of genera more or less remote 

 from them. If they are distinguished from the chelonians 

 by the absence of limbs and the presence of two penes ; from 

 the batracians, by undergoing no metamorphosis ; from the 

 saurians, by the want of eyelids, and from the fish by that 

 of gills, yet do they approximate, in some points, to all 

 these animals. Thus are they connected to the first by the 

 emys longicollis of Shaw ; to the second by the ccecUia ; to 

 the third by anguis ; and by hydrophis and pelamedis to 

 the last. 



There is nothing more wc derful and admirable in nature 

 than this sort of connection between the classes, orders, 

 groups, and genera of the aniraal kingdom. It is not a 

 regular gradation of being, like the steps of a ladder, accord- 

 ing to the Platonic system, nor do we think that it can be 

 very easily reduced to any definite plan, notwithstanding the 

 very ingenious and laudable attempts in this way, of some 

 recent naturalists. But we find in every class, and every 

 order of animals, connecting links with all the other classes, 

 and all the other orders. Somewhere or other, we are sure to 

 find the existing bond of afiinity. Thus we have flying mam- 



