ABSTRACTS OF PAPERS 227 



the corresponding phalanges of digit 2, manus of M. rohustus, as interpreted 

 by Owen. In Owen's reconstruction of M. rodustus the second and third pha- 

 langes of digit 2, manus, have undoubtedlj^ been interchanged with the corre- 

 sponding phalanges of digit 3, pes. 



In 1882 H. W. Harkness described what he believed to be imprints of a 

 sandaled human foot occurring in Pleistocene strata near Carson, Nevada. 

 These footprints were exposed, together with those of other animals, in the 

 stone quarries of the Carson State Prison yard. Shortly following this de- 

 scription Joseph Le Conte pointed out obvious objections to the theory of the 

 human origin of these footprints, namely, the large size of the individual im- 

 print and the span of the straddle. He suggested that the imprints were made 

 by a large quadruped, most probably a ground-sloth. The latter view was 

 entertained also by O. C. Marsh, who made comparison between the imprint 

 and the outlines of the pes of Mylodon. 



An interesting verification of the views of Le Conte and Marsh is suggested 

 by the restoration of the pes of Mylodon harlani from Rancho La Brea. The 

 posterior foot of this species corresponds very closely in size and shape with 

 the imprints found in the Pleistocene of Carson City, Nevada. 



TERTIARY NA8SIDJE OF THE WEST COAST OF AMERICA 

 BY STANLEY C. HEROLD 



(Abstract) 



A review of West Coast Tertiary species of the family Nassidse (Alectri- 

 onidse), ranging from Puget Sound to Ecuador, prepared in conjunction with 

 a discussion of the living Nassid^e from the same region by Mrs. Ida Oldroyd. 

 Their synonymy and stratigraphic range is established, certain forms are dif- 

 ferentiated and specifically named, and new species are described. An attempt 

 is made to determine their phylogenetic relationships, as evidenced by strati- 

 graphic and geographic distribution and faunal variations of the individual 

 species. 



ASTORIA SERIES (OLIGOCENE) IN THE REGION OF MOUNT DIABLO, MIDDLE 



CALIFORNIA 



BY BRUCE L. CLARKE 



(Abstract) 



The formations in the region of Mount Diablo, here referred to the Oligo- 

 cene, until comparatively recently were included in the Lower Miocene, being 

 correlated with the Temblor (Turritella ocoyana zone), as described by F. M. 

 Anderson from the region of the Temblor Mountains and near Kern River, in 

 the vicinity of Bakersfield, California. The beds of this horizon, as mapped in 

 different parts of the State by the United States Geological Survey, are re- 

 ferred to under the name of Vaqueros, which is the equivalent of the Monterey 

 group of Prof. A. C. Lawson. 



The first announcement of the separation of these Oligocene beds from the 

 Miocene was made by the writer in a short paper entitled "Occurrence of 



