270 



University of California Publications. 



[Geology 



the anterior limb. It is high and narrow with a deep terminal 

 cleft. A large subungual process is developed, and a large 

 foramen is present on the posterior-lateral angle of the process 

 which remains entire. The nature of the subungual process and 

 of the accompanying foramen suggests very strongly the char- 

 acters of the corresponding region in the terminal phalanges of 

 the gravigrade edentates. The deep terminal cleft and the entire 

 absence of any indication of a hood around the basal region of 

 the claw show that this form is a chalicothere and not a gravi- 

 grade. 



A somewhat similar but smaller and less compressed claw 

 from Virgin Valley shows the subungual process less developed. 

 There is in this specimen a large foramen on one side of the 

 basal process, and a much smaller one on the opposite side. The 

 character of the inferior region of the claw in these specimens 

 is not unlike that of the specimen of Macrotherium grande 

 figured by Deperet, 20 , though the subungual process appears to be 

 somewhat deeper in the specimen from Little High Rock Canon. 



A third claw (no. 10723) from Virgin Valley (figs. 44a and 

 446) is relatively shorter and thicker and the cleft is deeper. 

 The subungual process is scarcely developed and the basal fora- 

 mina are small. This claw is possibly from the posterior limb. 

 It was associated with the astragalus and calcaneum. 



The astragalus, no. 19404 (fig. 42), is very short, being 

 sharply truncated anterior to the trochlea, so that there is no 

 neck. The anterior articular surface shows no distinct articular 

 facet for the cuboid. The trochlear surface is broad and the 

 groove fairly deep. 



In the calcaneum, no. 19405 (fig. 41) the sustentacular region 

 is very prominent, though the sustentacular face for articulation 

 with the astragalus is not extraordinarily large. The external 

 face for articulation with the astragalus extends forward almost 

 to the anterior end of the bone. It also reaches inward to join 

 the sustentacular face, so that the interosseous ligament did not 

 separate them. 



With the material available one does not seem to be justified 



20 Deperet, C, Arch. Mus. Lyon, t. 5, pi. 4, fig. 7a, 1892. 



