Apr. 1903. North American Plesiosaurs — YVilliston. 9 



dorsal vertebrae from the Cretaceous, probably Benton, of Clark 

 County, Arkansas. Cope suppressed the generic name as of a genus 

 not sufficiently differentiated from Cimo/iasaurus. I believe, however, 

 that both genus and species are valid; and that the former will include 

 some of the species from Kansas. Lambe has identified the species 

 from the Belly River Cretaceous of Canada, but it seems to me that 

 the identity must be more or less problematical. 



ELASMOSAURUS. 



Cope, Proc. Acad. Nat. Sci. Phil. 1868, 68. 



•platyurus Cope, 1. c; Notes on Geology, Leconte, 1868, 68; Proc. 

 Bost. Soc. Nat. Hist. 1869, 266; Amer. Nat. iii, 87; Ext. 

 Batrachia, etc. 1869, 47, ff. 7-12, pi. ii, ff. 1-9, pi. iii; Amer. 

 Jour. Sci. 1870, 140, 268; Amer. Nat. v, 47; Rep. U. S. Geol. 

 Surv. Terr. 1871, 393, 1872, 320, 336; Cretac. Vert. 1875, 44, 

 79, 256; Bull. U. S. Geol. Surv. Terr, iii, 1877, 578; Amer. 

 Nat. xxii, 724; Leidy, Amer. Jour. Sci. xlix, 1870, 392; Proc. 

 Acad. Nat. Sci. Phil. 1870. 9, 18; Lydekker, Cat. Foss. Rept. 

 Brit. Museum, ii, 181 (Cimo/iasaurus). — Fort Pierre Cretace- 

 ous, Kansas. 



intermediis Cope, Proc. Amer. Phil. Soc. 1894, 112. — Fort Pierre 

 Cretaceous, South Dakota. 



0RIENTALI3 Cope, Proc. Acad. Nat. Sci. Phil. 1868, 313; Proc. Bost. 

 Soc. Nat. Hist 1869, 266; Geological Surv. New Jersey, 

 Cook, Append. (1868), 1869, 733; Amer. Nat. 1869, 87; Ext. 

 Batrachia, etc. 1869, 44, 55, pi. ii, f. 10; Amer. Jour. Sci. 

 1870, 368; Cretac. Vert. 1875, 255; Bull. U. S. Geol. Surv. 

 Terr, iii, 1877, 567, 578; Am. Nat. xi, 1877, 311; Leidy, Proc. 

 Acad. Nat. Sci. Phil. 1870, 22 {Discosaurus). — Greensand No. 

 4, New Jersey. 



skri'Iniinis Cope, Bull. U. S. Geol. Surv. Terr, iii, 578, 1877; Amer. 

 Nat. xi. 1S77, 311. — Niobrara Cretaceous, Nebraska. 



The genus Eiasmosaurus was founded upon a nearly complete 

 series of vertebra? obtained near the vicinity of Fort Wallace, Kansas, 

 wrongly ascribed to the Niobrara epoch. The neck was very long. 

 The incomplete girdles are also known. No additional material has 

 been ascribed to the type species since the original description by 



Cope. 



