506 GEOLOGICAL SUEVEY OF THE TEREITOEIES. 



As compared witli the corresponding parts of the Amphicyon vetus, 

 the specimen of this species displays the characters of the genus Canis. 

 The first tubercular molar is considerably smaller — not much more than 

 half as large, and the second very small, and supported by but one cy- 

 lindric root. The alveolar portion of the ramus is at the same time as 

 stout as that of the A. vetus. 



Canis lippincottianus, Cope, Synop. Vert. Col., 1873, p. 9. 



Among the numerous remains of dogs associated with those of ro- 

 dents and insectivora, I have observed several portions of mandibular 

 rami with teeth which indicate a species intermediate in size between 

 the Canis liartsliornianus and the C. gregarius. It was therefore not 

 very different from the coyote in size. Selecting one specimen as type, 

 which contains the teeth which correspond to those which represent the 

 species last described, 1 find the followkig peculiarities : The root of 

 the last molar is much compressed. There is only a trace of cingulum 

 on the x)enultimate, and the tubercles of the inner side of the crown are 

 well developed. Dimensions half as large again as in C. gregarius, as 

 indicated by many specimens of the latter. In it the anterior lateral 

 tubercles are subequal. 



A second specimen from the same locality is a mandibular ramus, with 

 the alveoli of the entire molar series and the last premolar and sectorial 

 perfectly preserved. As compared with a larger number of specimens 

 of C. gregarius, the jaw is larger, but is chiefly distinguished by the rel- 

 atively stouter and broader teeth. The first premolar is one-rooted. 



Measurements. 



M. 



Length of bases of crowns of M. II and III, (No. 1) 0.0095 



Length of base of crown of M. II 0060 



Width of base of crown of M. II .0035 



Elevation of crown of M. II 0030 



Length of bases of five anterior molars, (No. 2) 0320 



Length of bases of four premolars 0220 



Width of sectorial at middle 0045 



Elevation of sectorial at middle 0070 



Depth of ramus at sectorial 0130 



Thickness of ramus afc sectorial 0055 



Canis gregarius, Cope, Pal. Bull., No. 16, p. 3. 



About half the size of the red fox, ( Vulpesfulvus,) or equal to the V. 

 littoralis, Baird, but with relatively deeper mandibular ramus than 

 either. The premolars are in contact with each other, and the middle 

 posterior lobe is well developed, except in the first, which is also one- 

 rooted. Sectorial, with stout inner tubercle as high as the anterior lobe j 

 heel rather small. First tubercular with two roots relatively smaller 

 than in the species last described ; with two anterior and one posterior 

 tubercle. The second tubercular is very small, and has a single sub- 

 compressed or round root. It remains in very few specimens, and in a 

 few has evidently never existed. A premaxillary with part of the max- 

 illary bone displays parts and alveoli of two incisors, one canine, and 

 the first premolar. There is scarcely any diastema, and the canine is 

 compressed oval in section. The exterior incisor is quite large, exceed- 

 ing by several times the inner one. The premaxillary bone has but little 

 anterior production. 



