160 University of California Publications in Geology [Vol. 10 



ramus, no. 8422. from Potter Creek Cave, presents but insignificant 

 differences when contrasted with specimens from Rancho La Brea. 

 In addition to no. 8497, a number of upper and lower teeth were 

 regarded by Sinclair as pertaining to N. shastense. These specimens 

 resemble closely in size and shape corresponding teeth of the Rancho 

 La Brea species. Unless other characters favoring a specific separation 

 of the Rancho La Brea material are revealed, N. graciliceps must be 

 regarded therefore as synonymous with N. shastense. 



Dr. 0. P. Hay 36 has recently described as a new species, Noth.ro- 

 therium texanum, a damaged skull possessing the superior dental series 

 of one side but lacking the lower jaw. The specimen is reported to 

 have come from northern Texas, presumably from Pleistocene deposits. 



As indicated by Dr. Hay comparison between the Texas species and 

 N. shastense from Potter Creek Cave is restricted to loose teeth found 

 with the type ramus of the latter species. Of these, he considers speci- 

 mens figured by Sinclair 37 as representing the second and third teeth. 

 Specimen 8702 from Potter Creek Cave, represented in figures 3 and 

 3a of Sinclair's paper agrees very closely in size with the second 

 superior tooth of N. texanum. Dr. Hay believes that the teeth of 

 A r . texanum can be distinguished, for in no. 8702 "both the front and 

 the rear faces are convex in section, whereas both the second and the 

 third teeth of N. texanum have the front face convex and the rear face 

 concave." 38 In no. 8702 from Potter Creek Cave the posterior face 

 is not entirely convex, for as is shown in section there is developed 

 toward the outer side a slight but nevertheless distinct concavity. 

 Furthermore, in teeth from Potter Creek Cave, representing either 

 M- or M- of the superior dental series, the depth of this concavity 

 may vary greatly. 



Tooth 8337 from Potter Creek Cave, represented in figures 5 and 5a 

 of Sinclair's paper, is regarded by Hay as being the third (M-) of 

 the superior series. In the previous note on the Rancho La Brea 

 Not It roth erium. the writer stated that no. 8337 is probably of the 

 inferior dentition, a view which is still maintained. 39 



Hay, O. P., Descriptions of two extinct mammals of the Order Xenartbra 

 from the Pleistocene of Texas, Proc. U. S. Nat. Mus., vol. 51, pp. 107-123, pis. 

 3-7, 1916. 



37 Sinclair, W. J., New mammalia from the quaternary caves of California, 

 Univ. Calif. Publ. Bull. Dept. Geol., vol. 4, pi. 23, figs. 3, 3a, and 5, 5a, 1905. 



38 Hay, O. P., ibid., p. 121, 1916. In the present paper the superior teeth of 

 N 'othrotherium regarded by Hay as second and third have been designated M- 

 and M 1 respectively. 



39 Vide supra, p. 159. 



