1899-] Wortman and Matthew, Ancestry of the Canidce, etc. 131 



4, Molars reduced. 



Oliqobunis Cope. Dentition — . 



3-1-4-2 



0. crassivtiltus (Cope). No. 6903 (type). 



John Day. 



B. Modernized species. Long-footed, tetradactyl (functionally), with shear 



of sectorials nearly longitudinal, large brains and other advanced characters. 



1. Dental formula i-^. Otocyon. 



3-1-4-4 



2. Dental formula — . Canis, A^othocyon, Lycaon, Urocyon. 



3-1-4-3 



'^— I— 4. — 2 



3. Dental formula — Cvon. 



3-1-4-2 



4. Dental formula ^^ — . Icticvon. 



3-1-4-2 



VII. — An Ancestral Raccoon. 

 Phlaocyon leucosteus Matthew'' 



Founded on an exceptionally perfect skull and jaws, with a 

 nearly complete skeleton, discovered last summer by Mr. Handel 

 T. Martin of the American Museum Expedition of 1898 in north- 

 eastern Colorado. The level is the uppermost beds of the White 

 River formation, associated with Merycochcerus, Anchippus, Lep- 

 tauchcnia, Hyracodon, etc. The specimen was found in the rock 

 mixed with skulls and skeletons of two adult and three young 

 Merycochoeri, all within a space of six feet square. 



It represents a new and aberrant genus of Dogs, the characters 

 pointing clearly in the direction of the Raccoons, so that if we 

 adopt the genealogical conception of a family it must be placed 

 in the Procyonidae, although it is nearer to such primitive Dogs 

 as Cynodictis than to the modern Raccoons. 



Dentition. — (i) There is a small but clearly marked postero- 

 internal cusp on the upper sectorial, which, however, (2) retains 

 the triangular shape characteristic of the early Canidae. (3) The 

 dentition is that of Cynodictis and Canis, (4) but the cusps are low 

 and rounded. (5) Premolars small, stout, and crowded ; (6) 

 upper molars short transversely and subquadrate, as in Cynodon, 

 (7) the lower molars broad and low. (8) Canines short, the upper 

 ones not dagger-shaped, but curved as in the Dogs. (9) Incisors 

 in an even, transverse row. J^aw (10) short and thick, deep in 



' Bull. Am. Mus. Nat. Hist. 1899, 54. 



