100 University of California Puhlications in Geology [Vol. 12 



Locality. — Cotypes and figured specimens from Elsmere Canyon, 

 Los Angeles County, California, SW. of NW. i^, sec. 8, T. 3 N., 

 R. 15 W., San Bernardino B. L. and M., Univ. Calif, loc. 1602. 



ASTRODAPSIS GEANDIS Kew, n. sp. 

 Plate 17, figures la, Ih ; plate 18, figure 1 



Cotypes.— ISios. 11046 and 11047 Univ. Calif. Coll. Invert. Pal. 



Test very large. ^Measurements of specimen no. 11046 : antero- 

 posterior diameter 94 mm., transverse diameter 97 mm., greatest height - 

 15 mm. Upper surface greatly depressed around the submarginal 

 area, vv^ith margin markedly thin. Outline subcircular ; notches in 

 the ambulacral areas are all of the same size. Upper surface arched 

 regulai'ly to a central apex, the greatest arching taking place within 

 the area limited by half the distance from the margin to the apex. 

 Apical system central, moderate in size, and slightly depressed below 

 the highest elevation of the petals. Ambulacra wide, being broader 

 than the interambulacra at the margin ; dorsal portions petaloid. 

 Petals large, symmetrically arranged, extending about two-thirds the 

 distance to the margin ; slightly tumid, the tumidity being greatest 

 near the ai)ical system and ahnost negligible at the ends of the petals. 

 Inner rows of pores small, slightly elongated transversely, the two 

 rows converging but little, if any, toward the extremities of the petal ; 

 outer rows converge close to the inner ones when about two-thirds the 

 distance to the end. Abaetinal part of interambulacral areas flat, but 

 very faint, broad depressions may be present. Inferior surface slightly 

 concave to the peristome, the latter being central and slightly sunken. 

 Ambulacral furrows distinct, straight, continuing to the margin, and 

 extending over the upper surface nearly to the apex as median lines 

 on the petals ; in well preserved specimens faint processes are seen to 

 be given off from the main furrows on the under side about half way 

 to the margin ; these also continue over the superior surface along 

 the sutures between the ambulacral and interambulacral plates. Peri- 

 proct small, round, inframarginal, and situated close to the edge of 

 the test. Tubercles very small over the entire upper surface, and 

 larger and less crowded on the interporiferous area of the petals; 

 on the under side they are larger immediately around the peristome. 



Related forms.- — This species is most closely related to Astrodapsis 

 coalingaensis Kew, but differs in the greater average size; petals not 

 so highly raised ; thinner margin ; and test relatively less depressed. 



