94 University of California PuMicatio'ns in Geology [Vol. 12 



Related forms. — This form has been figured by Arnold as Astro- 

 dapsis whitneyi Remond, but Twitchell, recognizing that it was a dis- 

 tinct species, described it and gave to it the name A. anioldi. As this 

 name had already been used by Pack in A. antiselli var. arnoldi, now 

 raised to specific rank of A. arnoldi, it is here renamed A. calif ornicus. 

 This form differs from A. whitneyi in that it has much wider petals ; 

 the interambulacral areas are considerably more depressed, the tu- 

 bercles over the upper surface are not of uniform size, being larger 

 on the petals, and in that it lacks the distinctly bell-shaped appear- 

 ance. A. calif ornicus is most closel.y allied to A. coalingensis Kew, 

 but may be distinguished from it by having wider petals, more deeply 

 depressed interambulacral areas, more highly elevated petaliferous 

 areas, and a larger apical system. 



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

 mation), Upper Miocene. 



Localities. — Holotype from one mile north of Peerless Oil Co. 

 property, nine miles north of Coalinga, in big oyster beds, Univ. Calif, 

 loc. 3077. 



ASTRODAPSIS CIEEBOENSIS (Kew) 

 Plate 14, figures la, lb, Ic 



Astrodapshs tumidus subsp. cierboensis Kew, Univ. Calif. Publ. Bull. Dept. 



Geol., vol. 8, 1915, pp. 370-371, pi. 39, figs. 5a, 5h. 

 Astrodapsis tumidus subsp. cierboensis. B. L. Clark, Univ. Calif. Publ. Bull. 



Dept. Geol., vol. 8, 1915, pp. 400, 409, 410, 414, 415, 417, 424, 425 



(listed). 



Cotypes.—m^. 10061 and 10062 Univ. Calif. Coll. Invert. Pal. 



An echinoid of moderately small size. Average measurements: 

 anteroposterior diameter 36 mm., transverse diameter 32 mm., greatest 

 thickness 9.5 mm. Test subcircular to elliptical in marginal outline ; 

 strongly depressed ; margins thickened and rounded ; some specimens 

 slightly notched at the ambitus in the posterior ambulacral areas ; 

 abactinal portion of the interambulacral areas may be very faintly 

 depressed along the median line. Upper surface usually somewhat 

 flattened around the center. Summit anterior to the apical system, 

 the latter being central and slightly sunken. Ambulacra petaloid ; 

 petals slightly elevated, broad, and wide open at their extremities. 

 Pores conjugate ; inner rows of pores diverge widely and then contract 

 slightly about two-thirds the distance from the apical system to the 



