492 University of California Publications in Geology [ VoL - 10 



and relatively shallow, while in no. 19863 it is narrower and deeper. 

 In this respect the cave phalanx resembles more closely corresponding 

 phalanges of Megalonyx from Rancho La Brea. 



The Hawver Cave specimen differs from all second phalanges of 

 Nothrotherium known to the writer in a decidedly heavier construc- 

 tion. In this respect it is much more like the corresponding phalanges 

 in Megalonyx. 



Measurements of no. 19863 



Proximo-distal diameter through middle 58 mm. 



Transverse diameter of proximal end o30.5 



Dorsoventral diameter of proximal end a37 



Greatest dorsoventral diameter of distal end 33.4 



a, approximate. 



NOTHROTHEEIUM SHASTENSE HAWVERI, n. subsp. 



Among the vertebrate materials recovered from Hawver Cave, the 

 remains of Nothrotherium are undoubtedly the most conspicuous. 

 Not only is the genus represented by skull structures, but by other 

 parts of the skeleton as well. Comparison, especially of the dentition, 

 can readily be made between the Hawver Cave form and that occur- 

 ring in the other cave deposits and at Rancho La Brea. Where such 

 comparisons have been made, it is found that the Hawver Cave form 

 is typified by a M- slightly different from. the corresponding tooth 

 in Rancho La Brea specimens. This difference is held to be of sub- 

 specific importance and the new subspecies has been named in honor 

 of the late Dr. J. C. Hawver. 



Several teeth, and a skull fragment are comparable in size to the 

 corresponding parts in Nothrotherium shastense from Rancho La 

 Brea. With the exception of M- the teeth resemble closely in shape 

 those of the latter form. 



A portion of the maxillary (fig. 11) with a fourth superior tooth in 

 place is represented by no. 19864. In this specimen the two alveoli 

 in front of the tooth are partly represented as well as a portion of the 

 palate. The width of the palate measured between the alveoli of the 

 third superior teeth is as great as in skulls of N. shastense from the 

 asphalt beds. The crown of the fourth superior tooth is concave 

 laterally. Its triturating surface is worn to a median groove which 

 widens towards the inner side. The anterior edge of the wearing 

 surface is beveled. 



