358 BULLETIN 92, UNITED STATES NATIONAL MUSEUM. 



Cyrtoceras vassarina Dwight. 



Cyrtoceras Yassarina Dwight, Amer. Jour. Sci. Arts, 3d ser., 27, 1884, p. 254, pi. 



7, figs. 7, 7a, 8. 

 Canadian (Beekmantown) : Rochdale, New York. 



Cyrtoceras ventricosum Miller. 



Cyrtoceras ventricosa Miller, Cincinnati Quart. Jour. Sci., 2, 1875, p. 131, fig. 



16. James, J. F., Jour. Cincinnati Soc. Nat. Hist., 8, 1886, p. 246. Miller, 



N. A. Geol. Pal., 1889, p. 435, fig. 731. 

 Eden (Southgate): Cincinnati, Ohio. 



Cyrtoceras whitneyi Hall. 



Cyrtoceras whitneyi Hall, Rep. Sup. Geol. Surv. Wisconsin, 1861, p. 39. Whit- 

 field, Mem. Amer. Mus. Nat. Hist., 1, pt. 2, 1895, p. 65, pi. 9, fig. 5. 

 Richmond (Maquoketa): Maquoketa Creek, Iowa. 



Cyrtoceras(?) winonicuin Sardeson. 



Cyrtoceras(?) winonicum Sardeson, Bull. Minnesota Acad. Nat. Sci., 4, 1896, 



p. 102, pi. 6, figs. 2, 3. 

 Ozarkian (Oneota) : Near Dresbach, Winona County, Minnesota. 



CTRTOCERINA Billings. Genotype: C. ty pica Billings. 



Cyrtocerina Billings, Pal. Foss., 1, Geol. Surv. Canada, 1865, p. 178. Barrande, 

 Syst. Sil. Centre Boheme, 2, pt. 1, 1867, p. 451. Hyatt, Proc. Boston Soc. 

 Nat. Hist., 22, 1884, p. 266. Miller, N. A. Geol. Pal., 1889, p. 436. Holm, 

 Geol. Foren. Stockholm Forenhandl., 14, 1892, pp. 126, 209. Clarke, Geol. 

 Minnesota, 3, pt. 2, 1897, p. 774. Hyatt, Zittel-Eastman Textb. Pal., 1, 

 1900, p. 517; 2d ed., 1913, p. 597. 



Cyrtocerina madlsonensis (Miller). 



Tryblidium madisonense Miller, 18th Ann. Rep. Dep. Geol. Nat. Res. Indiana, 



1894, p. 318, pi. 9, fig. 38 (adv. sheets, 1892). Cumings, 32d Ann. Rep. 



Dep. Geol. Nat. Res., Indiana, 1908, p. 977, pi. 39, fig. 10. 

 Cyrtocerina madisonensis Miller and Faber, Jour. Cincinnati Soc. Nat. Hist., 



17, 1894, p. 32. Foerste, Bull. Sci. Lab. Denison Univ., 14, 1910, p. 74. 

 Richmond (Whitewater-Saluda) : Madison, Indiana. 



Cyrtocerina mercurlus Billings. 



Cyrtocerina Mercurius Billings, Pal. Foss., 1, Geol. Surv. Canada, 1865, p. 194, 



text fig. 179. 

 Canadian (Le vis) : Point Levis, Quebec. 



Cyrtocerina(?) schoolcrafti Clarke. 



Cyrtocerina(?) schoolcrafti Clarke, Geol. Minnesota, 3, pt. 2 1897 p. 774, pi. 



figs. 12-14. 



Black River (Decorah): Near Cannon Falls, Minnesota. 

 Holotype: Cat. No. 46526, U.S.N.M. 



Cyrtocerina typica Billings. 



Cyrtocerina typica Billings, Pal. Foss., 1, Geol. Surv. Canada, 1865, p. 178, 



fig. 159. Miller, N. A. Geol. Pal., 1889, p. 436, fig. 732. 

 Black River (Leray): Pauquette Rapids, Ottawa River, Canada. 



CTRTODONTA Billings. Genotype: C. rugosus and C. canadense Billi] 



Cyrtodonta Billings, Geol. Surv. Canada, Rep. Progr. for 1857, 1858, p. 1' 

 Canadian Nat. Geol., 3, 1858, p. 431; ibid., 4, 1859, p. 303; ibid., 6, 1861, 

 353; ibid., 7, 1862, p. 392. Meek and Worthen, Geol. Surv. Illinois, 3, 

 p. 310. Zittel, Handb. Pal., 2, 1881, p. 50. Salter, Mem. Geol. Surv. Gi 



