MIOCENE ECHINODERMATA. 211 



Clypeaster? gabbi Remond. 



Clypeaster gabbi Remond, 1863, California Acad. Sci. Proc, vol. 3. pp. 53, 54, no figure, 

 Clypeaster gabbi Meek, 1S64, Smithsonian Misc. Coll., vol. 7 (183), p. 2. 



Clypeaster gabbi Gabb, 1869, Geol. Survey California, Paleontology, vol. 2, pp. 36, 109, PL XII, figs. 64, 64a. 

 Clypeaster gabbi Cooper, 1888, Catalogue of California fossils: State Mineralogist Seventh Rept., p. 271. 

 (?) Scutella gabbi Merriam, 1899, California Acad. Sci. Proc, 3d ser., Geology, vol. 1, No. 5, p. 168, PI. XXII, 

 figs. 5, 5a. 



Description. — As the writer has been unable to examine any specimens which can be posi- 

 tively referred to this species, Remond's description is given verbatim: 



Disk rather small, comparatively thick, varying from circular to subpentagonal and irregular suboval. Apex 

 nearly central, subelevated; margin rounded; genital apparatus subangular. Ambulacral star almost symmetrical; 

 petals about equal in length, elongated, open at their extremities. Inferior surface flat near the edge and gently 

 concave in the center. Mouth depressed, subcentral. Ambulacral furrows straight, slightly marked. Anal aper- 

 ture very small, marginal. Tubercles of the upper surface numerous, especially in the ambulacra, round and 

 prominent. 



Dimensions. — According to Remond the " greatest diameter is 1.16 inches, smallest diame- 

 ter 1.10 inches, height 0.28 inch." 



Belated forms. — As Remond unfortunately failed to figure his form, and as no specimens 

 answering satisfactorily to his description are available, considerable uncertainty exists regard- 

 ing this species and its relations to other Californian echinoids. As stated in the discussion of 

 Scutella gahoi (Remond) Merriam (p. 1S9), the form described and figured by Merriam differs 

 in several important particulars which can not be ignored, and this renders it doubtful whether 

 Merriam has described and figured identically the same form as Remond. Additional collect- 

 ing at Remond's locality may result in discovering specimens answering to his description, 

 otherwise the species must remain of doubtful character. 



Locality and geologic horizon. — According to Remond, this species " occurs abundantly 

 on the eastern shore of San Pablo Bay, south of Mare Island, Cal., in soft sandstones of 

 Miocene age." 



Order ATELOSTOMATA. 



Suborder ASTERNATA. 



Family CASSIDULIDyE. 



Genus CASSIDULXJS Lamarck. 



Cassidtjlus bassleri Twitched, n. sp. 



Plate XCV, figures 5a-d. 



Determinative characters. — Test small, subovate to subcircular in marginal outline, broadest 

 posteriorly; upper surface convex, somewhat flattened on top, sides equally declining; margin 

 rounded on the sides and anteriorly, somewhat angular at the rostrated posterior end ; under- 

 surface concave centrally. Apex central; apical system excentric anteriorly. Ambulacral 

 areas rather broad in petaloidal dorsal portions, narrower elsewhere; poriferous zones broad, 

 outer row of pores slitlike or elongate elliptical. Peristome small, central, pentagonal to sub- 

 stellate, with large well-defined floscelle. Periproct oval, situated rather high above the margin, 

 in a short sulcus. 



Dimensions. — Length 2S millimeters; width 25 millimeters; height 14 millimeters. 



Description. — Specimens of this species have been known for some years; but it has usually 

 been confused with the Cretaceous species Cassidulus sequoreus Morton and so labeled in the 

 collections. It is named in honor of Ray S. Bassler, of the U. S. National Museum. The test 

 is small, rarely exceeding an inch in diameter; subovate to subcircular in marginal outline, 

 usually slightly broader posteriorly than anteriorly and slightly longer than broad. The upper 

 surface is moderately elevated, the height being equal to about half the diameter, convex, some- 

 what flattened on top from above the periproct to the apical system, equally declining anteriorly 

 and on the sides, posteriorly it slopes from above the periproct to the margin in a steep, oblique, 



