108 University of Calif omia Puhlications in Geology [Vol. 12 



concave, with well marked but shallow ambulacral furrows, which 

 extend undivided to the margin. Tuberculation distinct ; tubercles 

 relatively large, of the same size on both surfaces, not numerous, and 

 placed in well defined scrobicules ; mamelons of the tubercles on the 

 petals slightly larger ; small tiibercles present in the interspaces. Peri- 

 proct rather large, and placed immediately below the ambitus. 



Related forms. — This species resembles closely the young specimens 

 of Astrodeipsis coalingeiensis Kew, but may be distinguished readily 

 by the large size of the tubercles over both surfaces and by the rela- 

 tively thicker test. Prom Scat ell a merriami (Anderson) and *S^. ander- 

 soni Twitchell it may be distinguished by its scrobicular tubercles, less 

 undulating margin, and in that the anterior part of the upper surface 

 is not elevated. From S. gabhi (Remond) it differs in not having a 

 slightly supramarginal periproct, and in that the petals do not tend 

 to close. 



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

 mation), Upper Miocene. 



Localities. — Holotype from north of Coalinga, Fresno County, Cali- 

 fornia, Univ. Calif, loc. 2354. 



ASTEOD APSIS TUMIDUS Remond 

 Plate 14, figures .3a, Sb, Sc, 4a, 4b 



Astrodapsis tumidus Eenioml. Proc. Calif. Acad. Sci., vol. 3, 1863, pp. 

 52, 53, no figure. 



Astrodapsis tumidus. Meek, Smitlison. Misc. Coll., vol. 7, no. 183, 1864, 

 p. 2. 



Astrodapsis tumidus. Gabb, Geol. Surv. Calif., Pal., vol. 2, 1869, pp. 37, 



110, pi. 13, figs. 68, 68a. 

 Astrodapsis tumidus. Cooper, Cat. Calif. Fossils, Seventh Eept. Calif. 



State Mineralogist, 1888, p. 270. 

 Astrodapsis tumidus. Merriam, Univ. Calif. Publ. Bull. Dept. Geol., vol. 2, 



1898, no. 4, pp. 110, 111, 112, 117 (listed). 



Astrodapsis tumidus. Merriam, Proc. Calif. Acad. Sci., ser. 3, vol. 1, no. 5, 



1899, pp. 166-167, pi. 21, fig. 3. 



Astrodapsis tumidus. Stefanini, Boll. Soc. geol. ital., vol. 30, 1911, p. 703. 

 Astrodapsis tumidus. B. L. Clark, Univ. Calif. Publ. Bull. Dept. Geol., 



vol. 7, 1912, p. 54 (listed). 

 Astrodapsis tumidus. Kew, Univ. Calif. Publ. Bull. Dept. Geol., vol. 8, 



1915, pp. 366, 367, 370, pi. 39, figs. 7a, 7b, 7c; pi. 40, figs, lo, lb, 2. 

 Astrodapsis tumidus. B. L. Clark, ibid., pp. 400, 401, 404, 410, 411, 415, 



417, 424, 425, 426 (mentioned in text and lists only). 

 Astrodapsis tumidus. Clark and Twitchell, U. S. Geol. Surv. Mon., vol. 54, 



1915, pp. 202-203, pi. 95, figs. 3a, 3b; pi. 108, fig. A. 



