30 PROCEEDINGS OF THE ACADEMY OF 



coronoid the inferior part of the ramus is rounded, but narrower 

 than at the dental foramen. 



Measurements. M. 



Length from middle of base of coronoid to last exterior foramen 0.22 



" to last interior foramen 10 



Extent measured by four last interior foramina 064 



Depth (inner side) at basis coronoid 10 



" at last exterior foramen 079 



Greatest transverse diameter ramus at last external foramen . .042 

 Depth Meckelian tube at last external foramen 024 



" " "at mental foramen 047 



Width " " " " " 032 



" ramus two inches behind basis of coronoid process (where 



broken) 047 



Depth of do. at do. about 095 



The presence of coronoid process indicates that the present 

 species was a finner, and allied to Balsenopiera. Though there 

 are no vertebrae or other elements to determine its reference to 

 this genus or to its ally Eschrichtius, it may be proper to refer it 

 provisionally to the latter genus, since so many of its allies on 

 the Atlantic coast formations have been found to be referable to 

 it. This course is still more appropriate from the fact that the 

 strata of tertiary age near San Diego are reported to be of mio- 

 cene age, the same in which the eastern Eschrichtii have been 

 found. As to its specific characters, these differ entirel}- from 

 those of the latter. The ramus lacks the decurvature of most of 

 them. In size it approaches nearest the E. polyporus? Cope, and 

 E. prisms, Leidy. It is much less convex externally than the 

 latter. The exterior series of pores does not extend so far poste- 

 riori}^ as in E. polyporus, and the dental foramen has a superior 

 position, besides other differences. Size that of E. prisons. 



The species may bear the name of its discoverer, and be called 

 Eschriciiitus davidsonii, in recollection of the efforts of George 

 Davidson to aid the cause of science in various ways. 



This whale, when living, probably attained a length of about 

 forty feet. 



1 Proceed. Amer. Phil. Soc, 1870, p. 285. 



[June 25 



