Ee ae lle a eee ee E ss 
we eee 
1884.) Batrachia of the Permian Period of North America. 33 
not extend behind the orbits. This was a very abundant species 
FIG. 4.—- Trimerorachis i insignis Cope; parts of skeleton, natural size. Fig. @ basi- 
occipital, exoccipital and peri pore bones, posterior view; 4, angle of knibe, ex- 
ternal view; c, the same, posterior view ; d, n of vertebral column depressed by 
pr se showing the rad saaty nag (ï) and the pleuroc (2); ¢, a part of the 
vertebral column, oblique view, showing double Reun aes and zygapophyses. 
during the Permian period in Texas, and probably possessed 
aquatic habits, 
Eryors Cope. 
This genus is the best-known American representative of the 
Eryopide. This family includes also Acheloma, Anisodexis, and 
Probably Zatrachys in America, and Actinodon in Europe. The 
last-named genus occurs in the Permian beds near Autun, in Cen- 
tral France, and has been well elucidated by the labors of Pro- 
fessor Gaudry of the Jardin des Plantes. z 
In Eryops the teeth are arranged much as in Trimerortaghis in 
external series of nearly uniform size, with some large oħes in 
the anterior parts of both j jaws, a little within the external rows. 
As in that genus, the supra-temporal does not display a free ex- 
ternal margin, as it does in Cricotus, and there is no angular pro- 
cess of the mandible. There is, on the other hand, no lyra. The 
k intercentra and pleurocentra are much more robust than in 
Epiperorhachis The neural spines of the vertebre are large, and 
3 
