CEPHALOPODA. 221 



In 1858 Mr. Jules Marcou described Orihoceras Nova-Mexicanum, from the 

 Lower Carboniferous (Geol. North America). 



Mr. Hall described Orthoceras epigrus, from the Lower Carboniferous (Trans. 

 Alb. Inst., vol. 4). 



Prof. G. C. Swallow described 0. aculeatum, 0. moniliforme (not 0. moniliforme, 

 Hall, 1847) and 0. occidentals, from the Coal Measures; and 0. Kickapooense, 

 from the Upper Permian (Trans. St. Louis Acad. Sci.). 



In 1859 Mr. Billings described Orthoceras Antenor, 0. Maro and 0. Shumardi, 

 from the Chazy group; 0. Becki, 0. deparcum, 0. Lamarcki (=Endoceras 

 Lamarcki), O. Monlrealense (=Endoceras Montrealense) and O. sordidum, from the 

 Calciferous group (Canadian Nat. and Geol., vol. 4) ; also 0. Simpsoni, from the 

 Silurian (Geolog. Surv. Canada: Rep. of Progr.). 



Blr. Hall described Orthoceras clavatum (=0. desideratum, H., 1877), 0. Helder- 

 bergia, 0. longicameratum, O. pauciseplum, O. perstriatum, O. rigidum, 0. rude, 

 0. subtextile and 0. tenuiannulatum, from the Lower Helderberg group; and 

 0. arenosum, from the Oriskany sandstone (Paleontology of New York, vol. 3). 



In 1860 Prof. J. W. Dawson described Orthoceras elegantulum, and 0. exornatum, 

 from the Upper Silurian (Canad. Nat. and Geol., vol. 4). 



Mr. Billings described O. pertinax, 0. tenerum and Endoceras rapax, from the 

 Black-river group (Canad. Nat. and Geol., vol. 5). 



Mr. Hall described Orthoceras punctostriatum, from the Upper Silurian (Canad. 

 Nat. and Geol., vol. 5); 0. medullare and 0. columnare (=Orus, H., 1877), from 

 the Niagara group (Geolog. Surv. Wisconsin: Rep. of Progr.); and 0. Indianense, 

 from the Goniatite limestone of Rockford, Indiana (Thirteenth Rep. on N. Y. 

 Slate Cab. Nat. Hist.). 



Prof. Swallow described 0. Chemungense, from the Chemung, and 0. Chou- 

 teauense, from the Chouteau group (Trans. St. Louis Acad. Sci.) 



Mr. F. B. Meek described 0. baculum, from the Lower Carboniferous (Proc. 

 Acad. Nat. Sci. Phila.). 



Messrs. F. B. Mkek and H. A. Worthen published 0. expansum, from the St. 

 Louis group (Proc. St. Louis Acad. Sci.). 



