FOSSIL VERTEBRATES — AMPHIBIA 513 
24™ long and rather narrow, giving the skull a rather crocodilian 
appearance; the edges of the maxillaries were lined with small, 
nearly equal sized teeth that were opposed to a similar series on 
the lower jaw; besides the rows of teeth on the mawillaries there 
were a number of larger teeth on the palatines and the vomer, 
covering the roof of the mouth with a strong dentition. 
Metoposaurus (Metopias) from the Keupfer sandstone of 
Germany was nearly twice as large as Tvrematosaurus, the 
skull measuring about half a meter. The shape of the skull 
was much the same as in Evyops of the American Permian, being 
broad and stout, depressed from above downwards and showing 
a decided sculpture on the outer surface of the bones; the 
genus is peculiar for the very strong development of the 
pectoral shields, the interclavicle is a broad, diamond-shaped 
bone on either side of which are joined the clavicles that are 
also developed into broad plates, the whole covering the ventral 
side of the anterior portion of the body; all three of the bones 
exhibit a rugose outer surface. 
Capitosaurus from the same locality and horizon as Zvemato- 
saurus was nearly as large as Metoposaurus,; the orbits were small 
and elliptical; the nares large and located far forward; the 
extremity of the snout was broad and blunt. The same dentition 
is found in this as in the previous form, a series of small teeth 
on the edges of the upper and lower jaws and a few large tusk- 
like teeth on the palatines and the vomer; the surface of the 
skull shows a slight trace of the sensory canals and the bones 
are deeply pitted with grooves radiating outward to the edges of 
the bone. 
Mastodonsaurus from the Lettenkohl, the lower division of 
the Keupfer, reached the largest size of any of the Labyrintho- 
donti; the skull in some specimens reaching a meter in length. 
The skull was rather triangular in outline; the eyes were small 
and the nares located far forwards; the grooves marking the 
course of the sensory tracts are very distinct; there was a 
double instead of a single row of small teeth on the edges of the 
ps 
upper and the lower jaws and there were two or more enlargec 
