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University of California Publications in Geology [Vol. 11 



Specimen 21776 shows I 1 and I 2 with distinct cupping. On I 3 

 there is a marked infolding of the posterior wall and an incipient 

 posterior ridge begins to enclose a median pit. 



The upper canines of no. 21463 are of moderate size and slightly 

 flattened laterally. In no. 1349, apparently a form of the same 

 specific type, the superior canine is somewhat larger and apparently 

 is markedly flattened laterally. The inner face shows a median ridge 

 flanked anteriorly and posteriorly by shallow longitudinal grooves. 



Figs. 51a and 51b. Merychipptis calamarius stylodontus? , n. var. Superior 

 incisors and canine, no. 21463, X %. Fig. 51a, inferior view; fig. 51b, lateral 

 view. Barstow Miocene, Mohave Desert, California. 



Figs. 52a and 526. Merychippus calamarius stylodontus?, n. var. Inferior 

 incisors and canine, no. 21569, X %. Fig. 52a, dorsal view; fig. 52b, lateral 

 view. Barstow Miocene, Mohave Desert, California. 



Fig. 53. Merychippus calamarius stylodontus?, n. var. Inferior incisors and 

 canines, no. 21776, dorsal view, X %. Barstow Miocene, Mohave Desert, Califor- 

 nia. 



In a considerable number of specimens exhibiting the symphysial 

 region the lower canine is a large prominent tooth with nearly cir- 

 cular cross-section (fig. 52a) and the root is much larger than that of 

 I 3 . In no. 21776 the small inferior canine is situated immediately 

 behind I 3 . The root is approximately one-half as large as that of 

 L. This is possibly a female. 



