1004 BULLETIN 92, UNITED STATES NATIONAL MUSEUM. 



Plethocardia? cordiformis (Billings). 



Cyrtodonta cordiformis Billings, Canadian Nat. Geol., 3,*1858, p. 437; Geol. Surv. 



Canada, Kep. Progr. for 1857, 1858, p. 185; Geol. Canada, Geol. Surv. Canada, 



1863, p. 147, fig. 103a, b. 



Plethocardia? cordiformis Ulrich, Geol. Minnesota, 3, pt. 2, 1894, p. 577 (gen. ref .). 

 Cypricardites cordiformis Miller, N. A. Geol. Pal., 1889, p. 476 (gen. ref.). 

 Black River: St. Josephs Island, Lake Huron. 



Plethocardia suberecta Ulrich. 



Plethocardia suberecta Ulrich, 19th Ann. Kep. Geol. Nat. Hist. Surv. Minnesota, 

 1892, p. 245, fig. 29; Geol. Minnesota, 3, pt. 2, 1894, p. 577, pi. 40, figs. 25-27. 

 Trenton (Prosser): Near Cannon Falls, Minnesota. 

 Holotype.C&t. No. 46278, U.S.N.M. 



Plethocardia umbonata Ulrich. 



Plethocardia umbonata Ulrich, 19th Ann. Hep. Geol. Nat. Hist. Surv. Minnesota, 



1892, p. 244, fig. 28; Geol. Minnesota, 3, pt. 2, 1894, p. 576, pi. 40, figs. 22-24. 



Miller, N. A. Geol. Pal., 1st App., 1892, p. 701, fig. 1259. Grabau and Shimer, 



N. A. Index Fossils, 1, 1909, p. 416, fig. 537. 

 Black Elver: Six miles south of Cannon Falls, Minnesota (Decorah); Mercer 



County, Kentucky (Lowville). 

 Holotype.V&t. No. 46279, U.S.N.M. 



PLETHOMTTILUS Hall. Genotype: P. ponderosa Hall. 



Plethomytilus Hall, Pal. New York, 5, pt. 1, Lam., 1883, p. 4; 1st Rep. State 



Geol. New York, 1884, p. 15. Freeh, Zeits d. d. geol. Gesell., 40, 1888, p. 



364. Miller, N. A. Geol. Pal., 1889, p. 503. Whidborne, Mon. Dev. Fauna 



South England, 2, Pal. Soc., 1892, p. 52. Grabau, Bull. Buffalo Soc. Nat. Sci., 



6, 1899, p. 218. 



Plethomytilus cuneatus Kindle and Breger. 



Plethomytilus cuneatus Kindle and Breger, 28th Ann. Rep. Dep. Geol. Nat. Res. 



Indiana, 1904, p. 451, pi. 10, fig. 9. 

 Niagaran: Georgetown, Indiana. 



PLETHOPELTIS Raymond. Genotype: Agraulos saratogensis Walcott. 



Plethopeltis Raymond, Bull. Victoria Mem. Mus., 1, 1913, p. 64. 



Plethopeltis armatus (Billings). 



Bathyurus armatus Billings, Canadian Nat. Geol., 5, 1860, p. 319, fig. 23; Geol. 



Canada, Geol. Surv. Canada, 1863, p. 238, fig. 273; Pal. Foss., 1, Geol. Surv. 



Canada, 1865, p. 411, fig. 392. 

 Plethopeltis armatus Raymond, Bull. Victoria Mem. Mus., 1, 1913, p. 65, pi. 



7, fig. 18. 



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



Plethopeltis saratogensis (Walcott). 



Bathyurus armatus Walcott, 32d Ann. Rep. New York State Mus., 1879, p. 131. 

 Ptychoparia saratogensis D wight, Trans. Vassar Bros. Inst., 4, 1887, pp. 207-208. 

 Ptychoparia (Agraulos) saratogensis Walcott, Bull. U. S. Geol. Surv., 30, 1886, 



p. 21. Lesley, Geol. Surv. Pennsylvania, Rep. P 4, 1889, p. 844, figs. 

 Agraulos saratogensis Walcott, Proc. U. S. Nat. Mus.f 13, 1890, p. 276, pi. 21, fig. 



14. Weller, Geol. Surv. New Jersey, Rep. Pal., 3, 1903, pp. 118-119, pi. 1, 



figs. 7-9. Walcott, Smiths. Misc. Coll., 57, 1912, p. 269, pi. 43, figs. ll-15a. 

 Plethopeltis saratogensis Raymond, Bull. Victoria Mem. Mus., 1, 1913, p. 64. 

 Upper Cambrian or Ozarkian: Saratoga Springs and south of Poughkeepsie, New 



York (Hoyt); Blairstown, New Jersey (Kittatinny). 

 Cotypes.C&t. No. 23863, U.S.N.M. 



