50 



THE HISTORY OF THE PEEYCOSAURIA, WITH 



They have rounded 



The pra> and post- 



The ribs are articu- 



descending flange. Two intercentra preserved are broad and less completely crescentic ; 

 they still show large feces for the capitula of the ribs. 



There is no trace of vertebra; from the sacral region. 



Five anterior caudals are preserved (PL II, Figs. 27, 28, 29). 

 articular faces with broad funnel-like openings of the chorda! canal 

 zygapophyses are somewhat elevated on the broad neural arches, 

 lated to both the neural arch and the anterior edge; of the centrum. The division 

 is not complete into a capittilum and a tuberculum, but a deep groove on the posterior 

 side of the proximal end nearly accomplishes this. They are doubtless free in the most 

 anterior caudals. The ribs are short and slender. Those most anterior are the longest 

 and leave the vertebra, by a, strong curve upwards. The distal end of each rib well 

 below and in front of the anterior end of the centrum. The keels are low and rounded. 

 The spines are incomplete, but, were not, in all probability, so much elevated as in the 

 dorsal series. The three most anterior of the preserved caudals are in the natural position 

 and show that there was a considerable space between the lower edges of the centra. 

 The spaces were rilled by flattened intercentra with no facets for rib articulation; they 

 were however attached ligamentously to the capitular bead of the rib as this projected free 

 from the edge of the centrum. 



Several small vertebree are preserved from the distal end of the caudal series. They 

 are slender and cylindrical, biconcave and without spines or transverse processes. The; 

 gradual reduction of the series shows that the animal must have had a long and slender 

 tail. 



The scapuh (PI. Ill, Fig. 30) is falciform in outline. The body is elongate, 

 expanded and quite thill distally. It is so bent upon itself near the proximal cud that 

 the main portion lav, in life, more nearly parallel to the; vertebral column than perpen- 

 dicular to it. The lower edge of this portion is concave upwards. The bone is very thin 

 distally, but becomes thickened toward the middle of the shaft, due to the presence of a 

 strong ridge running back from the posterior edge of the humeral face to lose itself 

 on the distal end. A foramen penetrates the shaft just below (lie beginning of this ridge. 

 The anterior and superior edges are injured by decay and are incomplete. Cope figures 

 the anterior and the superior edges as nearly straight and as meeting at nearly a, right 

 angle. He also figures a face for the clavicle near the distal end. The scapula, and the 

 coracoid contribute about equally to the deep, obliquely placed cotylus for the humerus. 

 The edges of this cavity arc; marked by two strong projections, the upper, belonging to 

 the scapular portion of the region, looks forwards and downwards and the lower, the cora- 

 coid portion, looks backwards and upwards. The portion of the scapula bearing this face 

 lies at almost a right angle to the rest of the bone. 



