166 



KEY TO MARINE MAMMALS (Cont. 



12' Posterior margin of palate not notched, nearly a straight line 

 (Fig. 36); adult pelage not spotted except in some females that 

 have just reached maturity; adult female pale grayish with obscure 

 narrow whitish bands running transversely across lower back; adult 

 male dark brown with conspicuous broad light-colored bands, one 

 around neck and dorsal part of head and one around hind portions of 

 body, with branches directed anteriorly. RIBBON SEAL 



Figure 36. Seal skull comparisons; ventral view. 



RIBBON SEAL 



HARBOR SEAL. 



13 Claws more or less triangular in cross section, with distinct dorsal 

 ridge; pelage on back harsh to the touch, hairs coarse, tips pointing 

 directly backward; spots large and ring-shaped. For positive identif- 

 ication, skull is needed (see Fig. 29): skull of old individuals 

 without sagittal crest; mandibular teeth always aligned with jaw, 

 never crowded; first postcanines of lower jaw usually with three 

 cusps, the middle cusp largest; inner side of lower jaw between 

 middle postcanine teeth concave. RINGED SEAL 



13' Claws nearly semicircular in cross section, without distinct dorsal 

 ridge or growth rings, pelage on back smooth to the touch, hairs 

 finer, tips curved downward; spots small. For positive identifica- 

 tion, skull is needed (see Fig. 29): skull of old individuals with 

 low sagittal crest; mandibular teeth may be crowded out of line and 

 overlapping; first postcanine teeth of lower jaw usually with four 

 cusps, the second cusp from the anterior end largest; inner side 

 of lower jaw between middle postcanine teeth convex. 14 



