320 University of California Publications in Geology [Vol. 12 



Description op San Timoteo Pliocene Fauna 



The exploration of the San Timoteo has determined the former 

 existence of: 



Megalonyx?, sp. Plioliippus francescana, n. sp. 



Pliauchenia?, sp. Pliohippus francescana minor, n. subsp. 



Camelid, small, sp. Testudinate remains, two indet. sp. 



Cervid(?), medium, n. sp. 



MEGALONYX?, sp. 



Material.— Tyio cheek teeth, Univ. Calif. Coll. Vert. Pal. no. 23373 (fig. 29), 

 Univ. Calif, loc. 32.59. 



The writer referred these teeth to Dr. Chester Stock, who has very 

 kindly made the following report : 



Figs. 29a and 296. Megalonyx?, sp. Pig. 29a, last upper molar, no. 23373, 

 anterior view; fig. 29Z), fragment of tooth, X 1. San Timoteo beds, California. 



In so far as the material allows of determination, the genus Megalonyx seems 

 to be represented. Specimen 23373 (fig. 29a) is a fifth or last tooth of the left 

 superior series. It agrees closely in size and shape with a corresponding tooth 

 from the Pleistocene of Potter Creek Cave, which I have tentatively referred^i 

 to Megalonyx. The specimen, no. 23373, differs from the superior tooth of M. 

 jeffersoni in its smaller size, as indicated by the following comjDarison of 

 measurements: 



Megalonyx Megalonyx 

 No. 23373 jeffersoni wheatleyi 



Transverse diameter 14.7 mm. 21 mm. 17 mm. 



Anteroposterior diameter alO al4.8 10 



a, approximate. 



Contrasted with the fifth superior tooth in the maxillary of a ground sloth 

 (Univ. Calif. Coll. Vert. Pal. 22779)22 secured from the White Bluffs exposed on 

 the Columbia River near Hanford, no. 23373 is seen to differ decidedly in shape. 



21 Stock. Chester. Eecent Studies on the Skull and Dentition of Nothrotherium 

 from Eancho La Brea. Univ. Calif. Publ., Bull. Dept. Geol., vol. 10, pp. 137-164, 

 1917. 



22 Merriam, John C, and Buwalda, John P. Age of Strata Referred to the 

 Ellensburg Formation in the White Bluffs of the Columbia River. Univ. Calif. 

 Publ.. Bull. Dept. Geol., vol. 10, pp. 2.55-266, pi. 13, 1917. 



