462 FAMILY PHOCID.E. 



^ -IT. 3 



1. Muzzle narrow, regularly declined. lucisors ;j ^ simple, conical ; mo- 



lars, except first, 2-rooted, aud mostly 3-lobed. Digits of manus 

 slightly decreasing iu length from first to fifth, or first and second 

 subequal. Mamnue 2 Phoca. 



a. Skull broad, massive; general form thick; the limbs short; nose 



broad. Molar teeth large, crowded, obliquely implanted, especially 

 in youth and iu the lower jaw. Nasals considerably prolonged pos- 

 teriorly. Posterior nares narrow, the septum incompletely ossified. 

 Palatines deeply emarginate. Scapula sickle-shaped, the post-scap- 

 ular fossa greatly developed (Subgenus) Phoca. 



b. Skull thin, light; nose pointed, aud general form slender. Teeth 



small, slightly separated. Palatines, posterior nares, and narial 

 septum nearly as in the subgenus Pkoca. Nasals less prolonged 

 posteriorly. Digits of pes subequal. Scapula nearly as in Phoca. 



(Subgenus) Pusa. 



c. Skull, teeth, and general form nearly as in the subgeuus Pusa. Pos- 



terior nares broad (nearly twice as broad as high), the narial sep- 

 tum complete. Palatines truncate, or slightly emarginate ; never 

 deeply so as in Phoca and Pusa. Scapula nearly as in the typical 

 terrestrial Ferae not sickle-shaped, and with a broad pre-scapular 

 fossa. Sexes, when adult, widely different in coloration. 



(Subgenus) Payophilus. 



2. Muzzle broad ; forehead convex. Rudimentary supraorbital processes. 



Dentition weak ; the molars much separated, slightly implanted, 

 and partly deciduous or abortive in old age. Palatines broad, 

 emarginate. Middle digit of mauus the longest. Limbs small. 

 Scapula with no acromioii process. Whiskers smooth, attenuated. 

 Mammae 4 Erignathus. 



3. Cranial characters unknown. Dental formula as iu Phoca. Molars, 



except the first, 2-rooted, somewhat separated, with the crowns 

 simple and directed backward, as in Halichcerus. Sexes, when 

 adult, widely different in color Histriophoca. 



4. Muzzle broad ; skull much arched, increasing in height anteriorly. 



Molars single-rooted, except the last lower and the last two upper, 

 nearly simple or 1-lobed, conical. Whiskers crenulated. Digits of 

 manus as in Phoca Halichoerus. 



5. Muzzle elongate, depressed ; nasals, short ; skull somewhat depressed 



*) O 



posteriorly. Incisors j^-^, notched transversely on the inner side of 



the crown. Canines large. Molars thick, strong, obliquely and 

 closely implanted, imperfectly lobed, and only the three posterior 2- 

 rooted. Whiskers flat, smooth, tapering. Claws small, especially 



those of the pes Moiiachus. 



II. Zygomatic process of the maxillary and the malar bones nearly as in 

 the Phocina:. Interrnaxillaries not prolonged to meet the nasals. 

 Nasals very small. Supraorbital processes distinct, prominent, but 



c\ cy 



small. Incisors =- -^. Molars simple or plaited, not lobed. with a 



single club-shaped root CYSTOFHORHO3. 



6. Palatines short, slightly emargiuate, somewhat arched or vaulted. 



Auditory bulla3 square in front. Adult males with an inflatable 

 sack extending from the nose to the occiput. All of the digits with 

 claws strongly developed Cystophora. 



