RACCOONS OF NORTH AND MIDDLE AMERICA 27 



widely that the commonly accepted family alignment seems open to 

 some question. Potos contrasts strongly in nearly uniform coloration, 

 rounded ears, and long, tapering, short-haired, prehensile tail. The 

 rhinarium in Potos traverses the upper lip more as in Bassaricyon. In 

 the skull of Potos similarly striking contrasts with Procyon are evident. 

 The teeth may be regarded as somewhat similar in general form but 

 there the resemblance ends. The molar crowns in Potos are lower and 

 much simpler than in Procyon, being nearly flat and without well- 

 developed cusps at any age, the posterior molars almost completely 

 opposed, above and below. Anterior premolars, present in Procyon, 

 are absent in Potos, a condition correlated with the shortening of the 

 rostrum in the latter genus. The canines, normally rounded and 

 without distinct grooves in the adult stage in Procyon, are flattened and 

 saber-like, with deeply grooved sides in Potos. The mandible in Potos 

 is remarkable for its depth and long, early-fused symphysis, the space 

 between the rami anteriorly U-shaped instead of V-shaped, as is usual 

 in the group. The lower border of the ramus, convex in Procyon, is 

 concave in Potos, owing to lateral compression and downward expan- 

 sion of the angle. Among other differential cranial features of Potos 

 are the parallel-sided palate, peculiar flat bullae, and complete absence 

 of the mastoid processes so well developed in Procyon. 



The genus Procyon requires no close comparison with the Old World 

 procyonid genera Ailurus and Ailuropoda of the subfamily Ailurinae. 

 The characters of the Old World genera and their relationship to the 

 other procyonids have recently been discussed by Gregory (1936) and 

 by McGrew (1938). Among other important references bearing on 

 the classification of the Procyonidae are Hollister (1915), and Pocock 



(1921). 



KEY TO SUBGENERA 



a^. Pelage of two kinds, long guard hairs and short, soft underfur; hair on nape 

 normal, not directed forward; palate extending behind posterior molars a 

 distance of more than one-fourth length of palate Procyon (p. 28) 



a^. Pelage coarse and wiry, without underfur; hair on nape directed forward; 

 palate extending behind posterior molars a distance of less than one-fourth 

 length of palate Euproci/on (p. 80) 



LIST OF NORTH AMERICAN SPECIES AND SUBSPECIES, WITH TYPE 



LOCALITIES 



Subgenus PROCYON Storr 



Procyon lotor lotor (Linnaeus) Pennsylvania (p. 33). 



lotor hirtus Nelson and Goldman Elk River, Minn. (p. 37). 



lotor varius Nelson and Goldman Castleberry, Ala. (p. 38). 



lotor litoreus Nelson and Goldman Saint Simon Island, Ga. (p. -40). 



lotor solutus Nelson and Goldman Hilton Head Island, S. C. (p. 41). 



lotor elucus Bangs Oak Lodge, Brevard County, Fla. 



(p. 42). 

 lotor marinus Nelson Chokoloskee, Fla. (p. 44). 



