724 S. W. WILLISTON 



ilium was a strong one, as is shown by the large size of the sacral ribs, 

 it was clearly a yielding, ligamentous one. 



Pectoral girdle (Fig. 3). — The pectoral girdle lacks most of the 

 scapulae, save their clavicular ends, the outer angles of the clavicles, 

 and a portion of the coracoids. Otherwise it is in a remarkably 

 undistorted and natural condition. 



Scapula.— In the type specimen the extremity of the ventral 

 process is preserved in relation with the clavicles and interclavicle. 

 It is a flat, thin plate, underlapping the clavicle, meeting suturally 

 the clavo-coracoid process for a short distance, with its distal mesial 

 border slightly thickened, angularly, for cartilage. The outer part 

 of the plate is missing on both sides; it doubtless covered the clavicle 

 to the free border. 



Interclavicle. — The interclavicle is a large, triangular bone, with 

 a deep posterior emargination, and is strongly convex on its lower 

 surface from side to side. As seen from below, there is an elongate 

 process, with a small, narrow, slit-like emargination in the middle in 

 front. The visible border widens gradually for a considerable dis- 

 tance, and then turns outward sinuously to the hind angle. The real 

 border is underlapped in front by the clavicles, as is indicated by the 

 interclavicle of T. anonymum {Field Mus. Publ., No. 73, p. 44, f. 9), 

 continuing in front of the anterior end of the clavicles as a seeming 

 continuation of their borders. The posterior border is thin and 

 squamous, directed outwardly nearly transversely on each side of the 

 interclavicular foramen. It sends a pointed process back on each 

 side a third of the distance of the foramen, apparently, though 

 scarcely forming a part of the border of that opening. In the middle 

 there is a deep emargination forming a fossa continuing the foramen 

 anteriorly, its roof filled in by a thin bone suturally underlapping the 

 interclavicle. 



Clavicles. — The clavicles are elongate, triangular bones, in position 

 and shape resembling those of T. oshorni. The outer angle of each is 

 lost in the specimen. On either side of the interclavicle they are vis- 

 ible in front. The posterior outer border is also concave, beginning 

 in the angular depression lodged in the depression of the underside 

 of the clavo-coracoid processes. Just in front of these processes is the 

 arge interclavicular foramen, ovate in shape, rounded in front and 



