1920] 



Kew: Cretaceous and Cenozoic Echinoidea 



85 



of A. antiselU is biscuit-shaped ; and in that the poriferous areas of 

 the petals are comparatively wider. From A. calif orniciis Kew, the 

 species which Twitchell grouped under A. arnoldi (Pack), it may 

 be easily separated, for A. calif ornicus is larger, has a thinner test, 

 greatly sunken interambulacral areas, and no grooves along the sides 

 of the petals. In contrast with A. arnoldi peUoidcs (Anderson and 

 Martin), A. arnoldi (Pack) has much wider petals, and usually a rela- 

 tively thicker margin. In general shape it resembles A. whitneyi 

 Remond, but differs in having larger tubercles, a thicker margin, 

 wider petals, and interambulacral and ambulacral grooves. The small 

 grooves along the petals also separate it from A. tumidus Remond. 



Geologic range. — Lower Etchegoin (Jacalitos) formation. Lower 

 Pliocene. Associated with A. arnoldi var. fresnoensis Kew and A. 

 arnoldi var. depressus. 



Localities. — Holotype from Monterey County, California. Also 

 occurs in the Coalinga District, Fresno County, California, Univ. 

 Calif, loc. 2969 and 2973 ; Indian Valley, Goat Canyon, and Lynch 

 Creek of the Salinas Valley District, California. 



ASTEODAPSIS ARNOLDI DEPEESSUS Kew, n. var. 

 Plate 23, figures 2a, 2b, 2c 



Holotype— ^0. 11038 Univ. Calif. Coll. Invert. Pal. 



This form is distinguished from Astrodapsis arnoldi (Pack) by 

 its depressed test and by not having a bell-shaped appearance like the 

 latter, the upper surface being regularly rounded. Gradations can 

 be found between the two forms, and for this reason only a varietal 

 distinction is made. 



Geologic horizon. — Lower Etchegoin (Jacalitos) formation, Lower 

 Pliocene. Associated with Astrodapsis arnoldi arnoldi (Pack) and 

 Astrodapsis arnoldi var. fresnoensis Kew. 



Localities. — Coalinga district, Fresno County, California, Univ. 

 Calif. Iocs. 2969 and 2973. 



ASTRODAPSIS ARNOLDI CRASSUS Kew, n. subsp. 

 Plate 23, figure 1; plate 24, figures la, Ih, Ic 



Holotype.— ^0. 11350 Univ. Calif. Coll. Invert. Pal. 

 Test moderately large. Measurements of specimen no. 11350: 

 anteroposterior diameter 62 mm., transverse diameter 52 mm., greatest 



