5 2 



AMERICAN PERMIAN VERTEBRATES 



sub triangular in shape. The orbits, situated a little back of the 

 middle of the skull, are not large, trapezoidal in shape, the roof 

 somewhat convex, the anterior inferior angle acute. The plane of 

 their opening looks outward and a little upward. The otic notch 

 has for its roof the thickened outer border of the cranial table, 

 its immediate upper border undulating in outline, the anterior 

 ends somewhat constricted, both on the upper and lower margin, 

 by a slight protuberance, leaving the extremity in the shape of 

 about three-fifths of a circle, probably for the auditory meatus 

 and stapes. From the protuberance on the lower margin, the bor- 

 der of the notch curves downward and backward convexly to the 



Fig. iq. — Seymouria baylorensis. Skull and pectoral girdle, from the side, one- 

 half natural size, pm, premaxilla; m, maxilla; /, lachrymal; n, nasal; pf, prefrontal; 

 j, jugal; po, postorbital; sq, squamosal; qj, quadratojugal; cl, clavicle; ic. inter- 

 clavicle; sc, scapula; c, coracoid. 



quadrate articular end. The positions of the sutures, as shown in 

 the figure, will need no explanation. On the upper side, those made 

 out with tolerable certainty are indicated by lines of small crosses, 

 those copied from Broili by dots. I am least sure of the intertem- 

 poral, a remarkable stegocephalian bone unknown in other rep- 

 tiles; I think, however, there are indications of it in this specimen. 

 The sutures, as shown, agree clearly with those given by Broili. 

 The maxillary teeth are elongate and slender, curved downward 

 and gently backward. I cannot be sure of the number in the pre- 

 maxillae, but there were at least three, and the ones remaining are 

 shorter than those following them in the maxillae. I count eighteen 



