NEW PERMIAN VERTEBRATES 649 
the figure. In front of the border the surface of the bone is strongly 
convex from above downward, and somewhat so from side to side. 
This surface is pierced near its middle by the glenoid foramen. 
No sutures are visible distinguishing the bone into its three 
elements. As regards the cleithrum, there is a total absence of all 
indications of such a bone as occurs in Eryops, either on the upper or 
anterior border (Fig. 7). 
Clavicle and interclavicle-—The right clavicle was found in the 
matrix nearly in its anatomical position, its upper end only gone. 
It is very small for an amphibian, and has lost every trace of the pit- 
tings so characteristic of the stegocephalan clavicles on its outer surface, 
though not unlike the clavicles of Eryops. (See Williston, Kansas 
University Quarterly, VIII, 185, Pl. XXIX, Fig. 2.) The clavicle 
is bent near the middle nearly at a right angle, and somewhat twisted. 
The proximal part, underlying the interclavicle, is but moderately 
expanded—tless so, in fact, than in the contemporary reptiles, and not 
twice the width of the distal part. Its anterior border is thickened, 
its posterior, somewhat everted portion is thin. The scapular 
extremity is lost, but there is some, though doubtful, evidence of the 
possession of a small cleithrum, shown by a fragment of a small bone 
apparently attached to it. The greater part of the interclavicle is 
present in the specimen, lying on the under side of the procoracoid 
angle of the scapular bone. The bone is flattened and expanded 
transversely, with a short lateral projection on each side, and a thin 
but broad anterior margin. In the middle, posteriorly, the bone is 
slightly thickened, but there was no median posterior elongation, as 
in the reptiles. The interclavicle is remarkable for its small size, 
and thinness, as well as for the entire absence of external pittings. 
As a whole, the clavicular, as well as the scapular girdle is markedly 
reptilian in character, far more so than in any other known amphibian. 
Humerus.—Lying closely articulated in the right glenoid cavity 
was the proximal inner side of the right humerus as far as the median 
constriction. ‘The outer proximal part had been eroded away, and 
of the distal portion only the outline of the bone, and the inner distal 
part remained. Of the left humerus almost precisely the same 
proximal part was found loose in the wash, together with the distal 
half, with the exception of the inner distal part, that part left in the 
