1076 BULLETIN 92, UNITED STATES NATIONAL MUSEUM. 



Ptychaspis? selectus (Billings). 



Dikelocephalus selectus Billings, Pal. Foss., 1, Geol. Surv. Canada, 1865, p. 199. 

 Ptychaspis? selectus Walcott, Smiths. Misc. Coll., 57, No. 13, 1914, p. 352 (gen. ref.). 

 Ozarkian? (Levis — erratics): Point Levis, Quebec. 



Ptychaspis sesostris (Billings). 



Dikelocephalus Sesostris Billings, Pal. Foss., 1, Geol. Surv. Canada, 1865, p. 198, 



fig. 184. 

 Ptychaspis sesostris Miller, N. A. Geol. Pal., 1889, p. 564, fig. 1052. 

 Dicellocephalus Sesostris Matthew, Trans. Royal Soc. Canada, 1893, p. 11, footnote. 

 Ozarkian? (Levis — erratics): Point Levis, Quebec. 



Ptychaspis speciosus Walcott. 



Ptychaspis speciosus Walcott, 32d Rep. New York State Mus. Nat. Hist., 1879, 

 p. 131.— Lesley, Geol. Surv. Pennsylvania, Rep. P 4, 1889, p. 830.— Walcott, 

 Smiths. Misc. Coll., 57, 1912, p. 272, pi. 43, figs. 16-19. 

 Ozarkian or Upper Cambrian (Hoyt): Near Saratoga Springs, New York. 

 Cotypes.— Cat. Nos. 58563-58565, U.S.N.M. 



Ptychaspis stjbclavatus Billings. See Arionellus subclavatus. 



PTYCHOCRINUS Wachsmuth and Springer. 



Genotype: Gaurocrinus splendens Miller. 

 Ptychocrinus Wachsmuth and Springer, Proc. Acad. Nat. Sci. Philadelphia, 1885, 

 p. 321 (Rev. Pal., pt. 3, seel, p. 99). — James, Jour. Cincinnati Soc. Nat. Hist., 

 19, 1897, p. 109. — Wachsmuth and Springer, Mem. Mus. Comp. Zool., Har- 

 vard, 20, 1897, p. 197.— Bather, Geol. Mag., dec. 4, 6, 1899, p. 124; Treatise 

 on Zool., pt. 3, Echinoderma, London, 1900, p. 198. — Wachsmuth, Zittel- 

 Eastman Textb. Pal., 1, 1900, p. 145.— Zittel, Grundzuge Pal., 1, 1910, p. 

 161.— Springer, Zittel-Eastman Textb. Pal., 2d ed., 1913, p. 187. 



Ptychocrinus angularis Wachsmuth and Springer. See Ptychocrinus parvus. 



Ptychocrinus parvus (Hall). 



Glyptocrinus parvus Hall, 20th Rep. New York State Cab. Nat. Hist., 1867, p. 304 

 (nom. mid.); 24th Rep. New York State Cab. Nat. Hist., 1872, p. 207, pi. 5, 

 fig. 17 (separate, 1871, pi. 1, fig. 17).— Meek, Geol. Surv. Ohio, Pal., 1, 1873, 

 p. 36, pi. 2, fig. 4a, b — Miller, Jour. Cincinnati Soc. Nat. Hist., 6, 1883, p. 

 224. 



Ptychocrinus parvus Wachsmuth and Springer, Proc. Acad. Nat. Sci., Philadel- 

 phia, 1885, p. 322 (Rev. Pal., pt. 3, sec. 1, p. 100). — James, Jour. Cincinnati 

 Soc. Nat. Hist., 19, 1897, p. 110. — Wachsmuth and Springer, Mem. Mus. 

 Comp. Zool., Harvard, 1897, p. 199, pi. 18, figs. 1, 2. 



Glyptocrinus angularis Miller and Dyer, Jour. Cincinnati Soc. Nat. Hist., 1, 

 1878, p. 28, pi. 1, fig. 10. 



Gaurocrinus angularis Miller, Jour. Cincinnati Soc. Nat. Hist., 6, 1883, p. 229. 



?Glyptaster (Eucrinus) angularis Wachsmuth and Springer, Amer. Jour. Sci., 

 25, 1883, p. 265. 



Ptychocrinus angularis Wachsmuth and Springer, Troc. Acad. Nat. Sci. Phila- 

 delphia, 1885, p. 323 (Rev. Pal., pt. 2, p. 100). — James, Jour. Cincinnati Soc. 

 Nat. Hist., 19, 1897, p. 109. 



Reteocrinus gracilis Wetherby, Jour. Cincinnati Soc. Nat. Hist., 4, 1881, p. 83, 

 pi. 2, figs. 2a, 2.— Carpenter, Phil. Trans. Roy. Soc. London, 174, 1884, 

 p. 927.— James, Jour. Cincinnati Soc. Nat. Hist., 19, 1897, p. 103. 



Maysville (Fairmount): Cincinnati, Ohio, and vicinity. 



Plesiotype— Cat. No. 40774, U.S.N.M. (Holotype of R. gracilis.) 



