1056 BULLETIN 92, UNITED STATES NATIONAL MUSEUM. 



Pseudosphserexochus? eryr (Billings). 



Cheirurus Eryx Billings, Canadian Nat. Geol., 5, 1860, p. 322, fig. 30; Geol. 



Canada, Geol. Sur. Canada, 1863, p. 239, fig. 276 (fig. only); Pal. Foss., 



Geol. Surv. Canada, 1, 1865, p. 413, fig. 399. 

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



Pseudosphserexochus mercurius (Billings). 



Cheirurus Mercurius Billings, Pal. Foss., 1, Geol. Surv. Canada, 1865, p. 285, 



fig. 272. 



Ceraurus (Cyrtometopus) mercurius Clarke, Geol. Minnesota, 3, pt. 2, 1894, p. 736. 

 Pseudosphserexochus mercurius Raymond and Barton, Bull. Mus. Comp. Zool., 



54, 1913, p. 542 (gen. ref.). 

 Chazyan (Quebec-P): Cow Head, Newfoundland. 



PSEUDOSPHSEREXOCHUS (NIESZKOWSKIA) SATYRUS Raymond. See Nieszkowskia 

 eatyrus. 



Pseudosphaerexochus trentonensls Clarke. 



Pseudosphserexochus trentonensis Clarke, Geol. Minnesota, 3, pt. 2, 1894, p. 734, 

 figs. 53, 54. Weller, Geol. Surv. New Jersey Pal., 3, 1903, p. 205, pi. 15, figs. 

 ' 24, 25. 



Ceraurus trentonensis Miller, N. A. Geol. Pal., 2d App., 1897, p. 787 (gen. ref.). 

 Trenton: Trenton Falls, New York; Jacksonburg, New Jersey. 



Pseiidosphserexochus vulcanus (Billings). 



Cheirurus vulcanus Billings, Pal. Foss., 1, Geol. Surv. Canada, 1865, p. 284, figs. 



271a-c (not p. 324, fig. 310a-c=Nieszkowskia billingsi). 

 Pseudosphserexochus vulcanus Raymond, Ann. Carnegie Mus., 3, 1905, p. 367, 



pi. 14, fig. 16, fig. 10; 7th Rep. Vermont State Geol., 1910, p. 241, pi. 36, fig. 



16. Grabau and Shimer, N. A. Index Fossils, 2, 1910, p. 320, fig. 1634d. 

 Cheirurus prolificus Billings, Pal. Foss., 1, Geol. Surv. Canada, 1865, p. 285, fig. 



273, p. 325, figs. 311, 312. 

 Ceraurus (Pseudosphserexochus) prolificus Clarke, Geol. Minnesota, 3, pt. 2, 1894, 



p. 738 (gen. ref.). 

 Chazyan: Cow Head, Newfoundland (Quebec-P); Valeour Island, New York. 



PSEUDOSPH^EREXOCHUS VULCANUS var. BILLINGSI Raymond. See Nieszkowskia 

 billingsi. 



PSILOCONCHA Ulrich. Genotype: P. grandis Ulrich. 



Psiloconcha Ulrich, Geol. Surv. Ohio, 7, 1893, p. 665; Geol. Minnesota, 3, pt. 2, 

 1894, p. 530. Grabau and Shimer, N. A. Index Fossils, 1, 1909, p. 386. 



Psiloconcha elliptica Ulrich. 



Psiloconcha elliptica Ulrich, Geol. Surv. Ohio, 7, 1893, p. 667, pi. 52, figs. 3, 4; 



Geol. Minnesota, 3, pt. 2, 1894, p. 530, fig. 42c-d. 



Orthodesma ellipticum Miller, N. A. Geol. Pal., 2d App., 1897, p. 783 (gen. ref.). 

 Richmond (Waynesville) : Clarksville, Ohio. 

 Cotypes.Csit. No. 46281, U.S.N.M. 



Psiloconcha grandis Ulrich. 



Psiloconcha grandis Ulrich, Geol. Surv. Ohio, 7, 1893, p. 665, pi. 52, figs. 1, 2; 



Geol. Minnesota, 3, pt. 2, 1894, p. 530, fig. 42a-b. Grabau and Shimer, 



N. A. Index Fossils, 1, 1909, p. 386, fig. 489d-e. 



Orthodesma grande Miller, N. A. Geol. Pal., 2d App., 1897, p. 783 (gen. ref.). 

 Richmond (Waynesville): Waynesville, Ohio. 

 Holotype.-V*.i. No. 46283, U.S.N.M. 



