342 0. C. Marsh— Vertebrate Life in America. 
ians known from osseous remains are all of moderate size, 
but the foot-prints attributed to this group indicate animals 
larger than any of the class yet found in the old world. The 
Carboniferous Amphibians were abundant in the swampy trop- 
ical forests of that period, and their remains have been found 
imbedded in the coal then deposited, as well as in hollow 
stumps of the trees left standing. 
The principal genera of this group from American Car- 
boniferous rocks, are, Sawropus, known only from footprints, 
Baphetes, Dendrerpeton, Hylonomus, Hylerpeton, Raniceps, Pelion, 
Leptophractus, Molgophis, Piyonius, Amphibamus, Cocytinus, and 
Ceraterpeton. The last genus occurs also in Europe. Certain of 
these genera have been considered by some writers to be more 
nearly related to the Lizards, among true reptiles. Some other 
genera known from fragmentary remains or footprints in this 
. formation have likewise been referred to the true reptiles, but 
this question can perhaps be settled only by future discoveries. 
No Aniphibia are known from American Permian strata, but 
