138 CLASSIFICATION OF AMPHIBIANS. 



limits or their types. The custom^ also^ of giving new 

 names to groups long before unobjectionably named, 

 has been carried to such an extent in Germany, that 

 not only all the laws of nomenclature have been vio- 

 lated^ but so much confusion has thus been introduced, 

 that every one of these writers seems to consider it 

 necessary to invent a name, and make a genus, for the 

 animal he is abou to describe. With these obstacles 

 before us, we shaU confine our inquiries to what appear 

 to be the natural aiSnities of the larger groups alone ; 

 we shall, in fact, in this instance, pursue the synthetic 

 method, reserving the result of those researches now 

 in progress, for another opportunity. 



(138.) The primary groups, into which we shall now 

 distribute the Ophides, or serpents, may be thus briefly 

 stated. We have already shown that this order stands 

 between the Enalosaures, or swimming lizards, and the 

 true Hzards (^Saures). Between the terrestrial snakes 

 and the aquatic Enalosaures, there is, however, a group 

 of serpents which departs most materially from the rest 

 of the order by being aquatic, not merely so by oc- 

 casionally frequenting water, but by livmg entirely in 

 that element, and by possessing a structure suited to such 

 habits. These water serpents constitute, in our opinion, 

 the nearest approach to the aquatic or swimming lizards, 

 and we consequently place the HydrophidcB as the first 

 great group from which we commence our route. Now, 

 these water serpents are placed by M. Cuvier imme- 

 diately after those which are also decidedly venomous, 

 but live upon land, and possess a peculiar organisation. 

 "^Ve pass therefore, by means, probably, of the Platuri, 

 from the Hydrophidce to the Crotalidcp, — the most deadly 

 and terrific of aU serpents, and which are consequently 

 the most typical. Here we find the different species 

 of CrotaluSy or rattle-snake, the horned vipers of Africa 

 and India, and all those venomous groups to which 

 M. Cuvier has assigned particular characters. The 

 transition from these to the ColuberidiS is marked by 

 so many gentle gradations, that Linnaeus very often 



