CEPHALOPODA. 405 



Messrs. Meek and Hayden described JV. eccentricus, from the Permian system 

 (Trans. Albany Institute, vol. 4). 



In 1859 Mr. Billings described N.Jason, N. natator and JV. tyrans, from the 

 Chazy limestone (Canadian Naturalist and Geologist). 



In 1860 J. Hall described N. biserialis, from the Coal Measures of Iowa 

 (Geolog. Surv. of Iowa, supplement to vol. 1, pt. 2) ; Lituites capax [=N. capax] 

 and N. occidentalis (not N. occidentalis, Swallow, 1858), from the Niagara group 

 (Geolog. Surv. of Wisconsin: Rep. of Prog.); N (Discites) ornatus [=JV. Marcel- 

 lensis], Gyroceras liralum [=Nautilus liratus] and Gyroceras expansum, var. Saem. sp. 

 [= Nautilus], from the Hamilton group (Thirteenth Rep. N. Y. State Cab. Nat. Hist.). 



Messrs. Meek and Worthen described N. Chesterensis, N. spedabilis and N. 

 subglobosus (the latter since referred to N. globatus, Sow.), from the Carbonif- 

 erous limestone ; N. (Discus) digonus, from the Kinderhook group ; N. (D.) 

 planorbiformis and JV. (D.) Sangamonensis, from the Coal Measures (Proc. Acad. 

 Nat. Sci. Phila.). 



Mr. J. H McChesney described N. Forbesianus, N. lllinoisensis, N. quadrangulus 

 and JV. nodocarinatus, from the Coal Measures; and Cyrtoceras giganteum [=Nau- 

 tilus], from the Niagara group (New Paleozoic Fossils).* 



Prof. G. C. Swallow described JV. Gilpini, from the Coal Measures, and JV. 

 Lawsi, from the Hamilton group (Trans. St. Louis Acad. Sci.). 



In 1861 Mr. McChesney published Lituites cancellatus [=JV. cancellatus], from 

 the Niagara group (compare with Lituites= Nautilus capax). 



Messrs. Meek and Worthen described Nautilus (Trematodiscus) trisulcatus. 



In 1862 Mr. A. Winchell described JV. ingentior, Trematodiscus altidorsalis, 

 T. discoidalis, T. Meekanus, T. planidorsalis, T. striatulus, T. strigatus and T. trigo- 

 nus, from the Marshall group (Amer. Jour. Sci., 2d series). 



In 1865 Mr. Billings described JV. calciferus, JV. ferox and JV. Pomponius, from 

 the Calciferous group ; JV. desertus, JV. versutus and JV. insolens, from the Quebec 

 group (Palaozoic Fossils). 



* In a revision of this paper by Mr. F. B. Meek, in 1869, he makes the following synonoiny : Nautilus 

 <. Swallow, 1858,=iV. quadrangulus, McC, 1860,=iV. nodocarinatus, McC.,=iV. biserialis. Hall, 

 It is also to be remarked that these species are closely related to, if not identical with, [JV.] Discites 

 tuberculatm. Owes, 1852 (not JV. tuberculatus, Sowerby, 1821). 



