Vol. 6] Merriam: Virgin Valley and Thousand Creek. 



243 



Occurrence : Mascall or Rattlesnake Beds, eastern Oregon ; 

 locality 1101, Thousand Creek Beds, Thousand Creek, Humboldt 

 County, Nevada. 



Measurements 



No. 545 No. 12505 



M 1 , anteroposterior diameter 9.7 mm. 9.9 



M 1 , anteroposterior diameter at narrowest point be- 

 tween protocone and paracone 7.3 7.6 



M 1 , transverse diameter 13.3 </12.5 



a approximate, outer edge broken. 



CANISC?), sp.; near DAVISI, n. sp. 



A complete second lower molar (fig. 12) and the posterior 

 portion of a lower carnassial (figs. 13a and 13b) from Thousand 

 Creek, represent a small canid species apparently not far re- 

 moved from the existing Canis. 



The trigonid portion of M 2 consists of a small but nearly 

 centrally located protoconid and a considerably reduced meta- 

 conid. The heel consists of a small hypoconid with a basin-like 

 expansion of the entoconid region. The form of this tooth is 

 near that of M 2 in some of the existing forms of Canis, and there 

 seems reason for considering that this specimen represents a 

 form near that genus. 



On the fragment representing the lower carnassial, the meta- 

 conid is of moderate size. On the heel the hypoconid is consid- 

 erably larger than the entoconid, and is distinctly compressed 

 laterally, as is the entoconid also. This tooth was probably, but 

 not certainly, associated with the second lower molar described 

 above. 



This form is quite distinct from the species of Tephrocyon in 

 the structure of M 2 , and in the form of the heel of M 1 . The heel 

 of the inferior carnassial is narrower than in Tephrocyon, tin 1 

 tubercles are distinctly compressed laterally, and the entoconid 

 is relatively small. M., differs also from the forms referred to 

 Tephrocyon ( ?), sp. a and T. cf. rurestris in the narrowness of the 

 heel, and in the compression of its tubercles. 



It seems to the writer not improbable that the inferior molars 

 in no. 12543 are from an animal of the same species as the upper 

 molar referred to as Canis davisi; at any rate they represent a 

 closely similar canid type. 



