NATURAL SCIENCES OF PHILADELPHIA. 409 



There is no indication of the transverse fissures seen in Sphenodon 

 and many Lacertilia, nor are there any diapophyses on the caudal 

 vertebras preserved. 



Two vertebras accompanying the above are similar in general 

 characters, and appear to belong to the sacrum. If truly such, 

 they indicate a structure different from that seen in Lacertilia 

 and Crocodilia, and present some resemblance, perhaps only 

 superficial, to the Dinosauria. The centrum is much compressed, 

 and the articular extremities present a wide plane border below 

 the notochordal perforation. The corresponding part of the cen- 

 trum presents no indication of diapophyses. Neural arch lost. 



Some heads of ribs of appropriate size are compressed, and 

 exhibit a small tuberosity which is perhaps a rudimental capitulum. 

 They are much more lizard-like than those of Gr'icotus. 



The phalanges are of more slender form than those of Cricotus 

 and more like those of lizards, although less slender than usual 

 among: that order. The shafts are sometimes little, sometimes 

 much depressed. The distal condyle of one of the latter is not 

 emarginate. An ungual phalange is subconic, flat below, and with 

 a shallow groove above one of its lateral borders. 



A coracoid bone supports the greater part of the glenoid facet, 

 and exhibits also a facet for the scapula. These are flat, and not 

 excavated. Its form is that of an irregular right-angled triangle, 

 the base anterior and the outer angle truncated by the glenoid 

 facets. Its inner margin is thickened and truncated as though it 

 had been articulated with a mesosternal or opposite coracoid bone. 

 This may not be a correct interpretation of its appearance, for if 

 so, the arrangement would differ equal^ from that of Sphenodon, 

 Lacertilia, and Salamanders, and resemble that of the Saurop- 

 terygia. And it is not to be denied that there are other points of 

 resemblance to the coracoid of that order. There is an anterior 

 marginal facet as though for a clavicle, and a short, oblique, 

 posterio-internal one, as though adapted for a small sternum. 

 There is a shallow notch on the inner border anteriorly, corre- 

 sponding to one of those of the Lacertilia. 



This genus is more typically Rhynchocephalian than Cricotus. 



Specific characters. There is a shallow fossa in the entering 



angle between the superior and inferior articular facets of the 



front of the axis, and the centrum of the same is obtusely keeled 



below. The border of the anterior articular face of the dorsal 



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