The Serpents stand without doubt below the Lizards; yet it is difficult to arrange them properly into families. The poison-teeth appear to indicate a lower character, because the cranium is thereby removed or recedes from the usual type of structure, while the superior maxilla becomes very much arrested. But as there are moveable and immoveable poison-teeth, and the latter gradually pass over into the ordinary kinds of teeth, while externally 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.
Fam. 4. Mussel-Reptiles, Eel-like—Schuppenschlangen.
All the scales around the body small and of equal size; upon the belly only being somewhat larger. Here belong the venomous Hydridæ 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—Tafelschlangen.
Plates under the belly, those beneath the tail being halved or divided into two.
Here belong our Colubri, but also the venomous Adders.
Fam. 6. Kracken-Reptilia, Grundelartige—Schienenschlangen.
Entire plates upon belly and tail, as in the Rattle-snakes.
Order 3. Ancyliozooid Reptilia—Lizards.