MOODIE: PERMIAN ANPHIBIA. 251 



Length of cotylus 7.2 



Width of cotylus 3.8 



Diameter of inf raglenoid foramen 5 mm. 



Thickness of bone at lower edge 7 



Thickness of bone through cotylus 4.3 cm. 



Length of portion of cleithrum preserved 63 mm. 



Greatest width of cleithrum 22 



The clavicle of the right side is preserved almost completely 

 (plate LIII, figs. 1 and 2). The element was figured by 

 Doctor Williston but not described. It is strongly curved and 

 spatulate. Its outer surface is ornamented with longitudinal 

 grooves, which arise near the center of the bone and run each 

 way, thus indicating its ossific center. The inner surface of 

 the bone is smooth excepting for two vascular pits near the 

 center. A prominent ridge runs along the dorsal inner edge 

 of the bone. 



Measurements of the clavicle : 



Length along curve 24 . 7 cm. 



Length across arc 20 



Least width 1.8 



Greatest width 4.6 



Greatest thickness 1 



Least thickness 2 mm. 



There is a fragment of what I regard as the posterior 

 projection of the interclavicle. If it is such it is either a 

 pathological specimen or there were two projections from the 

 posterior edge of the interclavicle, for the fragment is highly 

 asymmetric. The spine, for such it is, has an irregular nodose 

 surface as if for the attachment of cartilage. It is long, slender 

 and somewhat flattened. (Plate LIII, fig. 3.) 



Measurements of spine of interclavicle : 



Length of specimen 13.7 cm. 



Greatest width 2.2 



Least width 75 



There are remains of about a dozen vertebrae preserved. 

 Portions of three of these are figured in plate LIV, figures 1 

 and 2. They all have the characteristic rachitomous form as- 

 sumed by the other species of Eryops. The divisions between 

 the pleurocentra, hypocentra and neurocentra are well marked. 

 The zygapophyses are well formed. The upper part of the 

 neural spines is much thickened, as is the case often in speci- 

 mens of Eryops megacephcdus Cope. According to Broili the 

 spines may also be bifurcate, as Cope has described for E. 

 erythrolithiciLS. The enlarged spine was undoubtedly for the 

 attachment of muscles to sustain the enormous head, and 



