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University of California Puhlications in Geology [Vol. 12 



average size ; in that the rows converge more closely toward the distal 

 end of the petals, and in that the slope of the upper surface is more or 

 less concave, whereas that of 8. fairbcinksi is markedly convex; more- 

 over, the ambulacral furrows are not so prominent on the actinal 

 surface. It may easily be distinguished from Dendraster (Calaster) 

 intcrlineatus (Stimpson) and D. (Calaster) oregonensis (W. B. Clark) 

 by its slightly anterior eccentric apical system. 



Geologic horizon. — Vaqueros formation. Lower Miocene. Associ- 

 ated with the fauna of the Turritella ineziana zone. Reported from 

 the middle part of the Sespe formation, 01igocene( 



Localities. — Holotype from ' ' near Torrey Canyon Wells, southwest 

 of Piru, Ventura County" (Arnold) ; also occurs "in tributary enter- 

 ing Little Sespe Creek at the Foot-of-the-Hill "Wells, Ventura County ' ' 

 (Arnold) ; Sespe Canyon, Ventura County, California (Pack, Ar- 

 nold) ; south side of Tar Creek Canyon, Ventura County, California, 

 Univ. Calif, loc. 2728 (Louderback) . South side of Santa Clara 

 Valley, Shiells Canyon, NW. 14 of Sec. 10, T. 10 S., R. 19 W., Ventura 

 County, California. 



SCUTELLA FAIEBANSKI SANTANENSIS Kew, n. var. 

 Plate 11, figures 3a, 3&, 3c 



Cotypes.—^oii. 11361 and 11362 Univ. Calif. Coll. Invert. Pal. 



This form differs from the typical Scutella fairbanksi Arnold in 

 its thinner test; the profile of the upper surface from the ambitus to 

 the summit is usually slightly concave or straight in contrast to that 

 of the »S'. fairbanksi, which is convex; the margin is more strongly 

 notched in the ambulacral areas, giving the test a broadly subovate 

 outline in some specimens ; and the summit coincides more closely with 

 the apical system. 



Related forms. — This variety is most closely allied to Scutella gabbi 

 var. tenuis Kew than is the typical form, but differs in having a 

 greater marginal notching in the ambulacral areas ; in attaining a 

 larger size ; and in that the rows of pores do not converge so much in 

 the distal ends of the petals. 



Geologic horizon. — Vaqueros formation, Lower Miocene. Associ- 

 ated with the fauna of the Turritella ineziana zone. 



Localities. — Holotype from Santa Ana Mountains, Orange County, 

 California, Univ. Calif, loc. 2339. 



