166 



ODOBJSNUS OBESUS PACIFIC WALRUS. 



zygomata share the general character of the anterior half of the 

 skull. 



FIG. 28. Odolcenus rosmarus. Adult. 



But equally striking differences are seen in a comparison of 

 the lower jaws of the two species. These differences correlate 



FIG. 29. Odolamus obesus. Adult. 



in a most interesting manner with those that characterize the- 

 cranium. Thus, in the Atlantic species (Figs. 28 and 30), the 



