136 MESOZOIC AND CENOZOIC ECHINODERMATA OF THE UNITED STATES. 



the test from the margin, which side branches soon bend and in turn approach the margin. A 

 small ridge extends along the center of each ambulacra! furrow for a short distance away from 

 the peristome. 



Tire periproct is very small, subcircular, on the under surface at a little more than one-third 

 the distance from the peristome to the posterior margin. It is sometimes nearer, sometimes 

 farther from the peristome than are the forks in the ambulacra! furrows. 



Belated forms. — P. pileus-sinensis is very closely related to P. lyelli and P. protuberans. 

 From the former it is best distinguished by its higher and straight or concave-sided central cone; 

 and from the latter by its lacking the swollen anterior interporiferous area at the apex. No 

 foreign forms appear to be closely related to this species. 



Localities.— The type was from "about 6 miles south of Black Oak Lock of the Santee Canal, 

 St. Johns Parish, S. C." The figured specimen came from "the Santee Canal, S. C." Other 

 localities are Santee River, S. O; near Tivoli, Beaehhaven Park, Limestone Creek, Towers, Rich 

 Hill, Crawford County; Shellstone Creek, 2 miles south of Perry, Houston County; and Ring Jaw 

 Landing, Oconee River, Ga. ; 1 mile west of Cocoa, Choctaw County; and Claiborne and below 

 mouth of Cedar Creek, Clarke County, Ala.; Chickasawhay River at Shubuta, Shubuta Creek, 2\ 

 miles north of Shubuta, and Shell Prairie near Pachuta, Miss. 



Geologic Ziorason.— Jackson formation, upper Eocene. In South Carolina in the Cooper 

 marl, of Jackson age. In Georgia in the Vicksburg or Jackson formation. 



Collections. — U. S. National Museum (5133, A; 137791, B); Amherst College; Boston 

 Society of Natural History; American Museum of Natural History; University of South Carolina. 



Family CLTPEASTRID^l. 



Genus CLYPEASTER Lamarck. 



Clypeaster eogersi (Morton). 



Plate LXIV, figures 2a-d, 3a-d. 



Scutella rogersi Morton, 1834, Synopsis organic remains Cretaceous, p. 77, PI. XIII, fig. 3. 



Lagana rogersi Agassiz, 1840, Cat. syst. ectyporum Echinodermatum fossilium musei Neocomensis, p. 6. Merely 



listed Morton's form, 

 non Scutella rogersi Agassiz, 1841, Mon. echinodermes vivans et fossiles, vol. 2, Des scutelles, pp. 85, 86, PL XIX, 



figs. 1—1. Described and figured Mortonella quinquefaria (Say) under the impression that he was dealing with 



Morton's form. 

 Scutella rogersi Morton, 1842, Acad. Nat. Sci. Philadelphia Jour., 1st ser., vol. 8, p. 218. 

 Scutella jonesii Forbes, 1845, Geol. Soc. London Proc, vol. 4, p. 574, text figure. 

 Scutella jonesii Forbes, 1845, Geol. Soc. London Quart. Join., vol. 1, p. 440, text figure. 

 Scutella rogersi, Agassiz (pars), 1847, Cat. raisonne echinodermes, vol. 7, p. 135. 

 Scutella rogersi Bronn (pars), 1848, Index palseontologicus, vol. 1, p. 196; vol. 2, p. 1126. 

 Scutella jonesii Bronn, 1848, Index pateontologicus, vol. 1, p. 196; vol. 2, p. 1126. 

 Clypeaster jonesii Desor, 1858, Synopsis des echinides fossiles, p. 243. 



Mortonia rogersi Desor (pars) (figure cited only), 1858, Synopsis des echinides fossiles, p. 231. 

 Scutella rodgersi Gabb, 1S59, Cat. invert, fossils Cretaceous, p. 19. 

 non Clypeaster ambigenus Michelin, 1861, Soc. geol. France Mem., 2d ser., vol. 7, p. 113. 

 Clypeaster jonesii. Dujardin and Hupe, 1862, Hist. nat. zoophytes echinodermes, p. 573. 

 Mortonia rogersi Conrad (pars), 1865, Acad. Nat. Sci. Philadelphia Proc, p. 74. 

 Mortonia jonesii Conrad, 1865, Acad. Nat. Sci. Philadelphia Proc, p. 74. 

 Mortonia turgida Conrad, 1865, Acad. Nat. Sci. Philadelphia Proc, vol. 17, p. 184, no figure. 

 Clypeaster jonesii Conrad, 1865, Acad. Nat. Sci. Philadelphia Proc, p. 74. 

 ? Mortonia tumida Conrad, 1866, Smithsonian Misc. Coll., vol. 7 (200), pp. 22, 37 (note). 

 Clypeaster jonesii Conrad, 1866, Smithsonian Misc. Coll., vol. 7 (200), p. 22. 

 ? Clypeaster tumidus Conrad, 1866, Smithsonian Misc. Coll., vol. 7 (200), pp. 22, 37 (note). 

 Clypeaster rogersi Conrad, 1866, Smithsonian Misc. Coll., vol. 7 (200), p. 22. 



Scutella (mortonia) rogersi De Gregorio (pars), 1890, Mon. faune eocenique Alabama, p. 250, PI. XLIII, figs. 16-20. 

 Clypeaster rogersi De Loriol, 1890, Soc. phys. hist. nat. de Geneva Mem., vol. suppl. du centenaire, p. 99. 

 Scutella rogersi Clark, 1891, Johns Hopkins Univ. Circ, vol. 10, No. 87, p. 77. 

 Eckinanthus rogersi Gregory, 1891 (discussion), Geol. Soc. America Bull., vol. 3, p. 105. 



Mortonia rogersi Gregory, 1891 (tabulation), Geol. Soc. America Bull., vol. 3, p. 105. This was evidently a lapsus calami.. 

 Scutella rogersi Boyle, 1S93, U. S. Geol. Survey Bull. 102, p. 263. 



