CEPHALOPODA. 225 



Mr. Worthem described 0. rectum and O. Unionense, from the Niagara group 

 (Geolog. Surv. III., vol. 6). 



In 1876 Mr. Hall published 0. luxum and 0. procerus, from the Schoharie 

 grit ; O. molestum, 0. Pelops var. Ohioense and 0. rudicula, from the Upper Hel- 

 derberg limestone; 0. Bebryx and 0. robustum (=0. Eriense, H, 1877), from the 

 Hamilton group; and identified 0. typus, Saemann (=0. Marcellense, Vanuxem), 

 from the Marcellus shale (Illus. Devon. Foss.) ;* and 0. simulator, from the Nia- 

 gara group {Twenty-eighth Rep. N. Y. State Mus. Nat. Hist.). 



In 1877 Mr. Hall proposed the following names for species before published 

 by him under preoccupied names: Orthoceras Clintoni for 0. subarcuatum II., 

 1847 ; 0. Ohrus for 0. vertebrate H., 1847 ; O. sociale for 0. gregarium H, 1861 ; 

 O. Orus for 0. columnare H, 1860; O. subcancellatum for 0. cancellatum H., 1852; 

 0. desideratum for 0. clavatum H., 1852 ; 0. stylus for 0. baculum II., 1862 (S. 

 A. Miller's Catalogue of American Palceozoic Fossils). . 



In 1879 Mr. Hall described Orthoceras Amycus, from the Niagara group at 

 Waldron, Indiana (Trans, of the Albany Institute, vol. X). 



Mr. C. D. Walcott described Orthoceras Oneidaense, from the Utica slate of 

 New York (Trans, of the Albany Institute, vol. X). 



The following American species of Orthoceras have been identified in Great 

 Britain, according to Morris' Catalogue of British Fossils, 1854 : 



Orthoceras arcuoliratum . Hall . Lower Silurian, Broughton. 

 0. bilineatum . . " Lower Silurian, Ayrshire. 



0. Brongniarti . . . Troost . Lower Silurian, Tyrone. 

 0. laqueatum . . . Hall . Upper Silurian, Westmoreland. 



0. vertebrale ..." . Upper Silurian, Presteign. 



* In 1853 Dr. L. Saeman.v described Orthoctra* ti/pus, from the limestone of the Marcellus shale, near 

 Caz'-niivia, X. T. (Daafefr emd Von Mtj/eri PalacmtograpMca). This species was recognized jus identical 



with 0. Marcdlerme of Vanitxem, in the Thirteenth Report on the State Cabinet of Natural History, 1860. 



29 



