120 University of California Publimtiom in Geology [Vol. 12 



poriferous zones of the paired petals have not so great a curvature; 

 and in that the angle between the petals of the bivium is not so large ; 

 averaging about 93°, whereas in the D. excentricus it averages 111°. 



Geologic horizon. — San Diego, lower San Pedro and Upper Fer- 

 nando formations, Upper Pliocene; associated with Dendraster paci- 

 ficus Kew. 



Localities. — (Holotype), Pacific Beach, San Diego County, Cali- 

 fornia (Calif. Acad. Sci. Coll.) ; Ventura County, California (Univ. 

 Calif. Coll.) ; and San Pedro, California (Leland Stanford Jr. Univ. 

 Coll.). 



DENDRASTER DIEGOENSIS DIEGOENSIS Kew, n. subsp. 

 Plate 29, figure 2; plate 30, figures 2o, 26 



Dendraster excentricus. Clark and Twitohell, U. S. Geol. Surv. Mon., vol. 

 54, 1915, pp. 223-225, pi. 104, figs. 1«, U, Ic, Id. 



HeAotype.—Ko. 12257, Univ. Calif. Coll. Invert. Pal. 



This form is separated from the other subspecies of this group by 

 having a test which is only moderately elevated and of smaller average 

 size. 



Geologic horizon. — San Diego, lower San Pedro, and Upper Fer- 

 nando formations. Upper Pliocene; associated with Dendraster 

 pacificus Kew. 



Locality. — Pacific Beach, San Diego County, San Pedro, Los 

 Angeles County, California, and Santa Clara Valley, Ventura County, 

 California. 



DENDRASTER DIEGOENSIS VENTURAENSIS Kew, n. subsp. 

 Plate 29, figures la, lb; plate 30, figure 1 



Dendraster excentricus. Clark ami Twitchell, U. S. Geol. Surv. Mon., vol. 

 54, 1915, pp. 223-225, pi. 105, figs, la, lb, Ic, Id. 



Holotype.— No. 11351 Univ. Calif. Coll. Invert. Pal. 



This subspecies is characterized by an exceedingly large test. 

 Measurements of specimen no. 11351 : anteroposterior diameter 46.5 

 mm., transverse diameter 104.7 mm., greatest height 7.8 mm. ; also 

 by the marked elevation of the abactinal surface within the area 

 limited by the length of the petals, which gives it a humped ap- 

 pearance. 



