164 



THE PERMO-CARBONIFEROUS RED BEDS OF 



Posteriorly both foramina open into the subscapular fossa, which has the 

 crescentic outUne characteristic of the Amphibia. There is a small and very 

 sharp pit on the outer face of one specimen just beneath the cotylus, but 

 this does not penetrate the bone and is probably adventitious. There are 

 strong articular faces for the coracoid elements, and it is evident that these 

 were suturally connected with the scapula during life. The anterior border 

 is incomplete in all the specimens, but it was apparently rounded. The 

 short and broad scapula is but another bit of evidence that Cricotus was 

 aquatic — if this scapula belongs to that genus. 



An ulna, radius, tibia, and fibula are here described as possibly belonging 

 to the genus Cricotus, though the association is based upon little more than 

 the appropriate size. They may very possibly belong to some other form. 



The ulna (No. 3423, fig. 37, h) has a large and well-developed cavity for 

 the condyle of the humerus confined entirely to the anterior face of the proxi- 



FiG. 37. — (a) Outer face, (6) posterior edge, (c) inner face of scapula of right side of Cricotus sp. ; 

 No. 3422. X %■ 

 {d) Radius, No. 3424; (e) tibia, No. 3425; (/) proximal face of tibia, (g) fibula, No. 3426; 

 (h) ulna, No. 3423. Lower limb bones provisionally referred to Cricotus (?) sp. X %• 



mal end. The inner face of the bone is nearly fiat. The whole bone is slightly 

 convex outward, with a suggestion of a sigmoid curve due to the expansion 

 of the outer side of the proximal end and the rather sharp incurvature of the 

 distal end. The distal face shows no division into facets and does not lie in 

 the same plane as the proximal end ; a slight twist of the shaft turns the outer 

 edge of the face slightly. The section of the shaft is oval-triangular, with 

 the greatest thickness at the anterior edge. Length 55.5 mm. 



The radius (fig. 37, d) is very simple. The shaft is somewhat flattened 

 and the articular ends are oval. On one side of the lower end the shaft is 

 flattened and the edge very thin and somewhat expanded. Length 44 mm. 



The tibia (fig. 37, e and/) is rather slender, with the proximal end slightly 

 enlarged and the face nearly triangular. Length 44 mm. 



The fibula (fig. 37, g) has an oval proximal face, the shaft is flattened, and 

 the distal end is much widened and divided obscurely into two facets. The 

 inner facet looks obliquely inward and downward and the outer facet looks 

 directly downward. Length 52 mm. 



Any or all of these bones may belong with the reptilian humerus No. 3354 

 (plate 24, fig. i). 



