374 BULLETIN 92, UNITED STATES NATIONAL MUSEUM. 



Cytherella? rugosa Continued. 



Cytherella? rugosa Jones, Cont. Micro-Pal., Geol. Surv. Canada, pt. 3, 1891, p. S9 

 (gen. ref.). Ulrich, Geol. Minnesota, 3, pt. 2, 1894, p. 686, pi. 43, figs. 21-24. 

 Grabau and Shimer, N. A. Index Fossils, 2, 1910, p. 366, fig. 1666, t, u. 



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



Trenton (Prosser) : Near Cannon Falls, Minnesota. 



Plesiotypes.Czt. No. 41814, U.S.N.M. 



Cytherella? rugosa a ret a Ulrich. 



Cytherella? rugosa var. arcta Ulrich, Geol. Minnesota, 3, pt. 2, 1894, p. 686, pi. 43, 



fig. 25. 



Trenton (Prosser) : Near Cannon Falls, Minnesota. 

 Holotype.Ca,t. No. 41815, U.S.N.M. 



Cytherella? subrotunda Uhich. 



Cytherella? subrotunda Ulrich, Geol. Minnesota, 3, pt. 2, 1894, p. 685, pi. 44, 



fig. 43. 

 Black River (Decorah) : Minneapolis, Minnesota. 



CYTHERINA ALTA Conrad. See Leperditia alta and L. jonesi. 

 CYTHERINA BALTHICA Hisinger (part). See Leperditia hisingeri. 

 CYTHERINA CRENULATA Emmons. See Cytheropsis crenulata. 

 CYTHERINA CYLINDRICA Hall. See Leperditia cylindrica. 

 CYTHERINA EMMONSI Vogdes. See Cytheropsis emmonsi. 

 CYTHERINA FABULITES Conrad. See Leperditia fabulites. 

 CYTHERINA PHASEOLUS Hisinger. See Leperditia phaseolus. 

 CYTHERINA SPINOSA Hall. See ^Echmina spinosa. 

 CYTHERINA SUBCYLINDRICA Emmons. See Cytheropsis emmonsi. 

 CYTHERINA SUBELLIPTICA Emmons. See Cytheropsis subelliptica. 



CYTHERODON Hall. Genotype: C. nasutus Hall. 



Cytherodon Hall, 23d Rep. New York State Cab. Nat. Hist., 1873, pi. 14, figs. 

 19-21; Pal. New York, 5, pt. 1, Lam. 2, 1885, p. 53. Miller, N. A. Geol. Pal., 

 1889, p. 477. 



Cytherodon? placidus Billings. 



Cytherodon? placidus Billings, Pal. Foss., Geol. Surv. Canada, 2, pt. 1, 1874, 



p. 137, pi. 8, fig. 10 (var. pi. 8, fig. 11). 

 Silurian: Arisaig, Nova Scotia. 



Cytherodon? soclalis Billings. 



Cytherodon? socialis Billings, Pal. Foss., Geol. Surv. Canada, 2, pt. 1, 1874, p. 138, 



pi. 8, fig. 12. 

 Silurian: Arisaig, Nova Scotia. 



CTTHEROPSIS McCoy. Genotype: C. aldensis Me 



Cytheropsis McCoy, Ann. Mag. Nat. Hist., 2d ser., 4, 1849, p. 414; Cont. British Pi 

 1854, p. 153; Synopsis British. Pal. Rocks., 1855, pi. 1 L, fig. 2. Jones, Ai 

 Mag. Nat. Hist. (3), 1, 1858, p. 248; Geol. Surv. Canada, dec. 3, 1858, p. 98.- 

 Barrande, Syst. Sil. du Centre Boheme, 1, Suppl., 1872, p. 508. Miller, 

 N. A. Geol. Pal., 1889, p. 541. 



