48 SYSTEMATIC PALEONTOLOGY 



the last named, and from the C. cephalus, it differs in the robust form of 

 the ramus, resembling in this respect rather such species as C. palceatlan- 

 ticum, S. priscus (Leidy), and S. expansus. 



" The fragment representing the S. darJcianvs is from the part of 

 the ramus anterior to the base of the coronoid process, and is about 

 350 mm. in length. Both faces are convex, but the external is more 

 strongly so than the internal. The superior part of the latter is, how- 

 ever, not horizontal as in the S. priscus, nor is the internal face sub- 

 horizontal as in 8. expansus. The two faces unite above at an obtuse 

 angle, which if perfect, would be nearly right. The inferior edge is 

 on the contrary a ridge which would be acute were it not rounded. 

 The section of the ramus is therefore lenticular, with one side more 

 convex than the other. Posteriorly the external convexity becomes 

 greater, and the internal convexity rises towards the base of the 

 coronoid, leaving a gentle concavity above the inferior border. The 

 external foramina are large, distant, and only a little further below 

 the superior ridge than those of the inferior internal row. The latter 

 are in two series; those of the superior smaller and quite near the 

 superior edge; the others larger and situated lower down, and separated 

 by intervals of about 40 mm. No trace of Meckelian or alveolar 

 grooves. 



Measurements. 



mm. 



f vertical 95 



Diameters at distal end \ , 



( transverse 7Z 



f vertical 114 



Diameters near coronoid i , 



(. transverse 99 



" The presence of two internal series of foramina distinguishes this 

 species from any of those known to me. The rami are less compressed 

 than those of the C. pusillum, while the external position of the exter- 

 nal foramina distinguishes it from the S. priscus (Leidy). The pres- 

 ence of an acute-angled ridge below distinguishes it strongly from the 

 C. palceatlanticum. The species was larger than the C etotherium 

 megalopliysum above described, having probably attained a length of 

 forty feet." Cope, 1895. 



