Tertiary Vertebrata of the West. 



517 



in the lower and middle portions of the deposit the genera are allied 

 to Canis, while in the Upper Miocene or Loup Fork beds the genus 

 Canis prevails. Eight genera of Dogs are here represented by 

 twenty-five species. Amphicyon of Lartet is known from three 

 species. A. cuspigerns is not larger than the Kit Fox ; A. harts- 

 homianus is about the size of a Coyote, and A. vetus rather larger. 

 Temnocyon has four species, and is distinguished from Canis by the 

 presence of a cutting edge on the superior face of the heel of the 

 inferior sectorial, in place of a double row of tubercles surrounding 

 a basin. This keel is a repetition upon that tooth of the heel seen in 

 the posterior premolar teeth of many Carnivora. The genus ap- 

 proaches most closely to the French form Cynodictis crassirostris. 

 On Temnocyon coryphceus the author observes that the dimensions 

 were about those of the Canis latrans, but the face was short. The 

 brain-case is smaller than in the Coyote. The genus Galecynns 

 of Owen is well represented by four species, which are characterized 

 by the relatively small size of their sectorial teeth. The internal 



Enhydrocyon stenocephalus. 



tubercle of the inferior sectorial is more largely developed than in 

 the later species of Dogs, and thus approaches some of the Viverridae. 

 The genus is separated from Canis by the presence of the epitrochlear 

 foramen of the humerus, a character shared with Amphicyon and 

 Temnocyon. G. gregarius is only about half the size of the Eed Fox. 

 G. geysmarianus was about the size of Mustela pennanii : it stood lower 

 on the legs than a Fox, had a body as slender as the most vermiform 

 of Weasels, and a tail as long as in the Ichneumons. G. lemur is the 

 smallest species yet discovered in the Miocene of Oregon. Enhydrocyon 

 has the canine type of dentition, but in the form of skull resembles 

 the Polecat and Otter : but one species is known, which was probably 

 as large as the Coyote. 



