82 EXPLANATIONS. 



above the butterfly, or the proteus as superior to 

 the land salamander, to establish his character as 

 a naturalist. Need I say that these Permian rep- 

 tiles are, in reality, by these facts degraded to a 

 place in proximity with fishes ? 



So much for the batrachia and lacertilia. 

 When we come to the great saurian line in the 

 Muschelkalk, Lias, Oolite, and Wealden, we have 

 a case which cannot be disputed, for here the ma- 

 rine character of the earliest of the series, and 

 their intermediateness between fish and true cro- 

 codiles are admitted by all. The first remove 

 from the fish is the ichthyosaur, its name declaring 

 the convention of class characters for which it is 

 remarkable. With piscine body and tail, and fins 

 advanced into a paddle form, it has a true croco- 

 dilian head. In the pliosaur, which is later in 

 appearing, we have a stage of advance to the true 

 sauria, which come forward in the oolite, in the 

 forms of teleosaurus, steneosaurus, &c. Afterwards, 

 chiefly in the Wealden, we have the dinosauria, 

 which betray an approach to the mammalian type. 

 Another oolite saurian, the cetiosaur, exhibits in 

 the form of the vertebrae a verging towards the 

 cetaceous mammalia. Here there is the most 

 perfect and even striking harmony with the theory 



