206 MESOZOIC AND CENOZOIC echinodeemata of the united states. 



Genus SCUTASTER Pack. 



Scutaster Pack, 1909, California Univ. Dept. Geology Bull., vol. 5, No. 18, p. 278, PI. XXIII, fig. 2. 



Description. — Test circular depressed, ambulacral star small. Lunules in the prolongation 

 of the petals of the trivium, and either lacking in the bivium and posterior interambulacral 

 space or not placed in the same relative positions as on the anterior portion of the test (Pack). 



This genus was founded on a single imperfect specimen found in the Miocene deposits of 

 California, which is also the type of the following species. Judging from the single figure which 

 Pack gives, there are good grounds for believing that the new genus should be recognized. 1 



Scutaster andersoni Pack. 



Plate XCIII, figure 1. 



Scutaster andersoni Pack, 1909, California Univ. Dept. Geology Bull., vol. 5, No. 18, pp. 278-279, PI. XXIII, fig. 2. 

 Scutaster andersoni Stefanim, 1911, Soc. geol. italiana Boll., vol. 30, p. 704. 



Description. — Only a single imperfect specimen of this species is known to exist, 1 and as 

 the writer has had no opportunity of studying it, the description of Pack is given verbatim: 



Test subcircular in outline, edges markedly tru,n. Upper surface regularly arched from the margin; apex anterior 

 to the center. Apical system small and apparently central. Ambulacral star small; petals extending slightly less 

 than halfway to the margin of the test, closed at the ends. Lateral petals broader than the posterior ones, but of almost 

 the same length. Poriferous zones broad, and continuing full width almost to the ends of the petals. In the posterior 

 petals the interporiferous area forms about one-third the width of the petal. Poriferous zones of the lateral petals 

 equal in width to those of the posterior petals, but inclosed area broader. In the extension of the three anterior petals 

 are broad lunules, over half as long as the petals; shallow grooves extend from the lunules to the margin. Anterior 

 lunule slightly farther from the apical system than are the lateral ones. From the ends of the posterior petals the 

 plates enlarge and the area broadens rapidly. No lunules were seen here, nor in the posterior interambulacral space. 

 They may be represented by marginal notches, as the posterior edge of the specimen is lacking. 



Dimensions. — Transverse diameter 44 millimeters; height 8 millimeters. 

 Locality. — East of Muir, Contra Costa County, Cal. 

 Geologic horizon. — Miocene. 

 Collection. — University of California. 



Genus ENCOPE L. Agassiz. 



Encope macrophora Ravenel. 



Plate XCIII, figures 2a-e; Plate XCIV, figures la-f, 2. 



Scutella macrophora Ravenel, 1842, Acad. Nat. Sci. Philadelphia Jour., 1st ser., vol. 8, pt. 2, pp. 334, 335, text figure. 



Encope macrophora Ravenel, 1848, Echinidae, recent and fossil, of South Carolina, p. 2. 



Scutella macrophora Tuomey, 1848, Geology South Carolina Rept., p. 208. 



Encope macrophora Ravenel, 1850, Am. Assoc. Adv. Sci. Proc, vol. 3, p. 160. 



Encope macrophora Tuomey and Holmes, 1S55, Pliocene fossils of South Carolina, pp. 2, 3, PL I, fig. 3. 



Non Scutella hexapora Desor, 1858, Synopsis des £chinides, p. 237. Desor evidently meant to give S. caroliniana 



Ravenel as a synonym of S. hexapora but gave S. macrophora instead. 

 Encope macrophora Meek, 1864, Smithsonian Misc. Coll., vol. 7 (183), p. 2. 



Ravenellia macrophora Liitken, 1863, Bid. til Kunds. om Echinoderme; Vidensk. Medd. KJ0benhavn. 

 Macrophora macrophora Conrad, 1865, Acad. Nat. Sci. Philadelphia Proc, p. 74. 

 Macrophora raveneli Conrad, 1865, Acad. Nat. Sci. Philadelphia Proc, p. 74. 

 Ravenellia macrophora Agassiz, 1S83, Mus. Comp. Zoology Mem., vol. 10, No. 1, p. 89. 

 Scutella macrophora Boyle, 1893, U. S. Geol. Survey Bull. 102, p. 263. 

 Encope macrophora Stefanini, 1911, Soc. geol. italiana Boll., vol. 30, p. 708. 



1 Since the above descriptions were written Pack has published some new information regarding this unique Californian form, based on 

 material recently discovered (California Univ. Dept. Geology Bull., vol. 7, No. 13, pp. 300-302, PI. XV, figs. 2a-b, 1913). The new data establish 

 the genus Scutaster on a firm basis. It is characterized by having but three lunules, which are situated in the anterior ambulacral areas. The 

 new specimens show that Scutaster andersoni is transversely suboval in marginal outline, with narrow notches opposite the three anterior petals 

 and broad shallow notches opposite the posterior pair. The apex is anteriorly and the apical system posteriorly excentrie. Longitudinal 

 diameter 53 millimeters; transverse diameter 62 millimeters; height 5 to 6 millimeters. The new locality is on the north slope of the San 

 Emigdio Mountains, at the southern end of the San Joaquin Valley, where the tests are said to occur in great abundance. In regard to geologic 

 horizon Pack says, "known only in the lower half of the Miocene." 



