PHYSETER. HYPEROODON. 15 



cranium raised into a compressed, semicircular crest. Cranium 

 above concave. Rostrum elongated, its base broad and thence 

 tapering to tip. Mandible long and narrow, the sj-mphysis being 

 more than half the length of the ramus. Vertebrae 50. Zygomatic 

 process of jugular, thick, massive. 



Fig. 4. Physeter macrocephalus — Lower Jaw. 

 No. 2^6 Field Columbian Museum Coll. 



22. macrocephalus. {PhyseUr), Linn. Syst. Nat., 1766, p. 107. 



Type locality. North Atlantic. 



Geogr. Distr. All seas. 



Genl. Char. Size enormous. Head about one-third the length 

 of body, high, truncated, compressed in front ; blow hole longitu- 

 dinal, placed to the left of the median line on the upper end. 



Color. Above black, shading gradually on the sides into the gray 

 of the under parts. Occasionall)^ specimens are piebald. 



Measurements. Total length of adult 55 to 60 feet, female much 

 smaller. 



11. nyperoodon. 



Hyperoodon, Lacep. Hist. Nat. Cdt., 1804, p. xliv. Type /i^. hutskopf 

 Bonn.,=/r. rostratus Miill. 

 Upper part of head anterior to blow hole rising abruptly from 

 above the snout ; upper ends of premaxillae rise and expand laterally 

 and overhang the nares ; nasals concave along median line and ante- 

 riorly their outer edges expand over the front of inner border of the 



