NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 



175 



The second type of scapula is represented by two or three different forms. 

 The first of these (No. 3437) is shown in plate 24, figures 6 and 7 and figure 48, /. 

 The posterior edge of the blade is slightly injured by decay, but it is apparent 

 the line was slightly concave. The anterior edge is nearly straight and is 

 directly continuous with the strong anterior edge of the supraglenoid fossa. 

 The supraglenoid fossa is much larger than is common, due to the very pos- 

 terior position of the posterior edge, which carries the articular portion of the 

 cotylus. The fossa is deep and at its base there is a deep pit in the position 

 of the foramen in the scapulae described above, but there is no perforation of 

 the bone. The articular surface for the coracoid elements presents a most 

 peculiar outline, due to the strong development of the anterior and posterior 

 edges of the epicondylar fossa. 



A fragmentary coracoid (No. 3444, fig. 49, a and h) in the collection evi- 

 dently belongs with this type of scapula. So far as can be told, the outline 



Fig. 49. — Unnamed reptiles. X %■ 

 (a) showing strong ridges and position of the foramen, (t) 



articular face for scapula of coracoid. No. 3444. 

 (c) posterior edge, (d) outer face of scapula of left side. 



No. 3436. 



was rounded, but the proximal portion, where it articulated with the scapula, 

 is marked by two strong ridges, between which lies the foramen. The outline 

 of the articular surface corresponds with the face of the scapula just described. 

 The peculiarities of these bones indicate the existence of an animal that can 

 not be placed in any group as yet described ; it is very possible that they belong 

 to some form of amphibian. 



Another form of scapula, resembling the preceding but smaller, is repre- 

 sented by two specimens, one (No. 3436, fig. 49, c and d) with a fragment of 

 the coracoid attached and one less perfect. The anterior edge of the blade is 

 more concave and the whole blade is more slender. The anterior edge of the 

 supraglenoid fossa is not so prominent and the fossa is less deep, without the 

 pit. It is possible that these are from immature individuals. 



