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University of California Puhlications in Oeology [Vol.12 



ambulacra petaloid. Petals broad, slightly elevated, and extending 

 more than one-half the distance from the apical system to the ambitus ; 

 the posterior pair the longest, with the odd anterior pair somewhat 

 shorter than the others. Odd petal differs from the paired ones in 

 that it is considerably wider, and the rows of pores do not tend to 

 converge at their extremities. Inner rows of pores of the paired 

 petals converge slightly near the extremity ; outer rows at first diverge 

 and then converge to a greater degree, joining the inner rows at the 

 ends of the petal. Interporiferous area about twice the width of each 

 poriferous area, except in the odd anterior petal, in which it is much 

 wider, though the poriferous area has the same width as in the other 

 petals. Inferior surface nearly fiat, faintly concave to the mouth. 

 Peristome round and of comparatively small size. Ambulaeral fur- 

 rows well marked, straight, undivided, and extend to the edge of the 

 test. Periproct round, small, and situated in a small notch in the 

 margin. 



Belated forms. — This Lower Miocene Scutella is most closely re- 

 lated to Scutella fairhanksi Arnold, from which it differs in that it 

 is much larger and has a more depressed test, the upper surface is 

 less regularly rounded to the summit, and the periproct is strictly 

 marginal, whereas in the S. fairhanksi it is supramarginal. It is 

 separated from 8. norrisi Pack by having less pronounced triangular 

 marginal notches, and by petals which are not fully open at their 

 extremities. 



Geologic horizon. — Upper part of Vaqueros formation. Lower 

 Miocene ; associated with Turritella ineziana Conrad and Pecten i-ivag- 

 nolia Conrad. 



i:oca/,%.— Specimen 447 from NE. 1/4 of Sec. 16, T. 20 S., R. 6 E., 

 Vaqueros Creek, Monterey County, California, locality 140, Calif. 

 Acad. Sci. Coll. Pal.; cotypes from Salinas River district (Leland 

 Stanford Junior Univ. Coll. Pal.). 



Genus ASTROD APSIS Conrad (emended) 



Astrodapsis Conrad. Proc. Acad. Nat. Sci. Phila., vol. 8, 1856, p. 315; 



U. S. Pac. R. E. Expl., vol. 7, Pal. Kept., 1857, p. 196. 

 Astrodapsis. Remond, Proc. Calif. Acad. Sci., vol. .3, 1863, p. 52. 

 Astrodapsis. Clark and Twitchell, U. S. Geol. Surv. Mon., vol. 54, 1915, 



p. 197. 



Genotype. — Astrodapsis antiselli Conrad, specimen no. 165466a 

 U. S. Nat. Mus. 



