1920] Kew: Cretaceous and Cenozoic Echmoidea 101 



From A. whitneyi Remond it differs in having its petals less strongly 

 elevated, and with larger tubercles on them ; in its greater size ; in 

 having a more nearly circular test with smaller notches in the margin 

 in the posterior ambulacral areas ; and in having a relatively more 

 depressed test. 



Geologic Jiorizon. — Upper San Pablo group (Santa Margarita for- 

 mation), Upper Miocene, above the "Big Blue" horizon. Found 

 associated with Astrodapsis coalingaensis Kew. 



Localities. — North of Coalinga, Fresno County, California. Co- 

 types from Univ. Calif, loc. 2268. 



ASTEOD APSIS JACALITOSENSIS Arnold 

 Plate 20, figures la, Ih 



Astrodapsis jacalitosensis Arnold. U. S. Geo!. Surv. Bull., no. 396, 1909, 



pp. 63-64, pi. 15, fig. 5. 

 Astrodapsis jacaUtosensis. Arnold and Anderson, IT. S. Geol. Surv. Bull., 



no. 398, 1910, p. Ill, pi. 37, fig. 5. 

 Astrodapsis jacaUtosensis. Stefanini, Boll. Soc. geol. ital., vol. 30, 1911, 



p. 703. 



Astrodapsis jacaUtosensis. Clark and Twitcliell, U. S. Geol. Surv. Mon., 



vol. 54, 1915, pp. 203-204, pi. 95, fig. 4. 

 Astrodapsis jacaUtosensis. Nomland, Univ. Calif. Publ. Bull. Dept. Geol., 



1916, vol. 9, p. 202 (listed). 



Holotype.—'No. 165610 U. S. Nat. Mus. 



Size large. Measurements of specimen no. 11037 Univ. Calif. Coll. 

 Pal. : anteroposterior diameter 67 ( ?) mm., transverse diameter 79 mm., 

 greatest height 20 mm. Marginal outline suboval, the greatest diam- 

 eter being usually in the anteroposterior direction ; test considerably 

 elevated, rounding concavely from summit to margin, the latter being 

 somewhat thickened and notched in the ambulacral areas. Apical 

 system central and deeply sunken. Petals broad, of the same size, 

 and markedly raised near the summit of the test, but becoming flush 

 with the surface about one-half the distance from the apical system 

 to the margin. Petals wide open, and with very slight tendency to 

 close. Pores continue to the margin, the double rows diverging from 

 each other but little. Interambulacral areas of the upper surface 

 have almost imperceptible broad depressions with faint grooves along 

 the sides of the petals in the ambulacral areas.' Inferior surface 

 slightly concave, with distinct broad ambulacral furrows, which extend 

 from the mouth to the edge of the test. Tubercles small, numerous, 

 and of the same size on both actinal and abactinal surfaces. Anus 



