36 



AMERICAN PERMIAN VERTEBRATES 



reptile I have observed for the first time in any form other than the 

 amphibia the inner opening of the foramen or canal back of the 

 border of the subscapular fossa, which I have called the glenoid 

 foramen. That the canal perforates the bone to open in the glenoid 

 fossa I am not prepared to affirm. I find, however, that the fora- 

 men is also present in the Diadectidae, and perhaps in other cotylo- 

 saurians. Its presence removes the last distinguishing character 

 between the temnospondyl and cotylosaurian pectoral girdles. One 



may distinguish them now only by 

 the smaller size of the cleithrum 

 in the reptiles ! 



The suture separating the pos- 

 terior coracoid is situated not far 

 back of the supracoracoid fora- 

 men, which is imusually large. 

 The limits of the anterior cora- 

 coid are not distinguishable; the 

 bone is thinned, rounded on the 

 anterior angle, which is slightly 

 underlapped by the clavicle, and, 

 with the metacoracoid, is curved 

 inward nearly to a horizontal 

 plane, approaching its mate of the 

 opposite side, but separated by 

 the stem of the interclavicle. The 

 interclavicle reaches a little farther 

 back than the hind angle of the 

 metacoracoid, and is of moderate width; its front part is dilated 

 and mostly hidden from view, as in the other Permian reptiles. 



In each skeleton there is a pair of bones found lying just back 

 of the coracoids, and nearly below the vertebrae, of the nature of 

 which I am not fully satisfied, though there would seem to be little 

 doubt but that they are unusually large hyoids (Plate XXXVIII, 

 Fig. 2). They are about three inches in length, greatly expanded 

 on their distal, thin end, with a somewhat curved and narrowed 

 shaft deeply concave in outline on one side, less so on the other, 

 thickened and truncate for articulation at the proximal end. The 



Fig. II. — Limnoscelis paludis. 

 Interclavicle and hyoid, two-fifths 

 natural size. 



