165 



KEY TO MARINE MAMMALS (Cont.) 



Figure 35- Fur seal head comparisons 



NORTHERN FUR SEAL 

 ADULT c? 



10 Six incisors at front of upper jaw (Fig. 29); hind toes nearly equal 



in length. 11 



10' Four incisors at front of upper jaw; inner and outer hind toes clearly 

 longer than middle three; color grayish to brownish (pups very dark, 

 black), not spotted or banded; when molting, large patches of fur 

 appear to drop off, giving a (false) diseased appearance. 



NORTHERN ELEPHANT SEAL 



11 



IT 



12 



Whiskers smooth, thick, straight, conspicuously bushy; third digit 



of foreflipper longest, the flipper being broad and blunt with all 



claws near tip; no longitudinal ridge of bone on top of skull; 



mammary teats four; teeth of adults loosely rooted, often worn down 



to surface of jaw or lost entirely; spaces between teeth behind 



canines almost tooth wide. BEARDED SEAL 



Whiskers beaded, slender, curled, not bushy; third digit of fore- 

 flipper shorter than first and second; the flipper tapered with 

 digits decreasing in length from first ("thumb") to last; sagittal 

 crest present in some species; mammary teats two, teeth of adult 

 firmly rooted; spaces between postcanine teeth less than tooth wide. 12 



Posterior margin of palate distinctly notched or incised (Fig. 36); 

 adult pelage may be spotted. 



13 



