Vol. 6] Merriam: Virgin Valley and Thousand (.'reek. 245 



Occurrence: Thousand Creek Beds; locality 1100, Thousand 

 Creek, Humboldt County, Nevada. 



Measurements 



No. 12543 



M x , anteroposterior diameter of heel 5.5 mm. 



M,, transverse diameter of heel 6.4 



M 2 , anteroposterior diameter 8.5 



M 2 , transverse diameter 6. 



CANID, FORMS INDETERMINATE 



A number of scattered limb bones from Virgin Valley and 

 Thousand Creek represent several canid forms, and possibly 

 belonging to some of the species described above. 



Several small astragali (fig. 15) obtained at different locali- 

 ties are apparently to be referred to the same form, which is 

 possibly a species of Tephrocyon. They are characterized by a 

 sharply-defined shelf at the anterior end of the trochlea and by 

 the rather marked lateral twist of the neck. 



An' astragalus representing another type of canid is shown 

 in figure 16. 



INDETERMINATE HUMERI 



The distal end of a carnivore humerus from Virgin Valley 

 (no. 10650) and one from Thousand Creek (no. 12553) repre- 

 sent two distinct generic types. Both may be feline or they may 

 both represent a primitive dog-like form. 



In specimen 10650 (fig. 14) the broad distal region of the 

 humerus shows a strongly developed inner condyle and supinator 

 ridge, and a large supracondyloid foramen is present. The 

 supinator ridge extends upward as a sharp ridge to the narrowest 

 portion of the shaft, where the bone is broken off. 



In specimen no. 12553 the distal end is no wider than in no. 

 10650, and the shaft is much smaller, but the anteroposterior 

 diameter of the trochlea is much greater. The olecranon fossa 

 is also much larger than in no. 10650. 



