630 BIOLOGY. 



pass over into the ordinary kinds of teeth, while exter- 

 nally also, no character has been found to distinguish 

 the venomous from the non- venomous Serpents, it is 

 best at present to discontinue this separation. 



Then the Serpents can be brought according to the 

 structure of their scales into 3 families. They are 

 either of equal and small size, around the whole body ; or 

 there are plates upon the belly and tail ; or finally, the 

 plates under the latter are divided into two tablets. 



FamA. Mussel- Reptiles, Eel-like Sclmppenschlangen. 



All the scales around the body small and of equal 

 size ; upon the belly only being somewhat larger. Here 

 belong the venomous Hydridse or Sea-snakes, and huge 

 Boas or Pythons. If once the venomous Serpents could 

 be distinguished as a distinct family, they will indeed 

 be placed higher, and the non-venomous be separated 

 from them. Then probably the Boas may be raised, 

 together with their allies, as the highest family. 



Fam.5. Snail-Reptiles, Haddock-like Tafelsclilangen. 



Plates under the belly, those beneath the tail being 

 halved or divided into two. 



Here belong our Colubri, but also the venomous 

 Adders. 



Fain. 6. Kracken-Reptilia, Grundelartige Schienen- 

 schlangen. 



Entire plates upon belly and tail, as in the Rattle- 

 snakes. 



Order 3. Ancyliozooid Eeptilia Lizards. 



3545. Scales, the usual kind of teeth and tongue ; 

 inferior maxillae anchylosed in front, mastoid bone not 

 freed, mostly feet and eyelids. 



They divide likewise into three families. 



Fam. 7. Worm-Reptiles, Tunny-like Schleichen. 



Body round and serpentiform, with small scales, feet 

 rudimental, or even wanting. 



Here belong the Caecilise, Blind-worms, and Scinci. 

 I have united these animals, which elsewhere have stood 

 dispersed among the Serpents and Lizards as well as 



