University of California Publications. 



[Geology 



Measurements of Humerus 



No. 10650 No. 12553 



Greatest width of distal end 35.8 mm. 



Width from bottom of trochlear groove to extreme 



outer side 18.4 18.4 



Least anteroposterior diameter of trochlea 8.2 11.6 



Width measured from middle of lower end of supra- 



eondyloid foramen to outer condyle 27. 27. 



Anteroposterior diameter of shaft forty-five milli- 

 meters above the distal end 12.4 10. 



PROCYONIDAE 



PEOBASSAEISCUS ANTIQUUS MATTHEWI, new genus and new variety 



Type specimen no. 12539, Univ. Calif. Col. Vert. Palae. From 

 the Virgin Valley Beds ; locality 1095, Virgin Valley. Humboldt 

 County, Nevada. 



Probassariscus , new genus. Characterized by the presence of 

 a well-developed paraeonid ridge on M 2 , and by the greater width 

 of the heel and better development of the entoconid region of 

 M 2 than in Bassariscus. 



In the collections from Virgin Valley there is a single lower 

 jaw fragment, with the posterior four teeth (figs. 21a and 21&), 

 which represents a form closely related to the form described as 

 Bassariscus antiquus from the Snake Creek Beds of western 

 Nebraska. The differences in dimensions which appear are not 

 considered for the present as indicating more than a varietal 

 separation from the Snake Creek species. The Virgin Valley 

 form is named in honor of Dr. W. D. Matthew. 



The jaw fragment represents an animal of approximately the 

 same size as the Recent B. astuta. The mandible is slightly 

 higher than that of the Recent specimens used for comparison, 

 but is not thicker. A large mental foramen is present below 

 the middle of P 3 . A much smaller foramen is present in B. 

 astuta under the anterior root of this tooth. 



In the inferior dental series of the specimen from Virgin 

 Valley, Mj is absolutely smaller and M 2 absolutely larger than 

 in the living species, and M„ is relatively considerably larger than 



io Matthew, W. D., & Cook, H. J., Bull. Am. Mus. Nat. Hist., vol. 26, 

 p. 377, 1909. 



