...J,, PALAEONTOLOGY OF NEW YORK. 



Hudson-river group; also the genus Endoceras, embracing the following 

 species: E. gemelliparum and E. subcentrale, from the Black-river limestone; 

 E. longissimum and E. multilubulatum, from the Black-river and Trenton lime- 

 stones ; E. angusticameratum, E. annulatum, E. approximation, E. arctiventrum, E. 

 distans, E. duplicatum, E. magniventrum, E. protetforme var. elongatum, E. protei- 

 forme var. lineolatum, E. prot. var. strangulatum, E. prot. var. tenuistr latum and 

 E. prot. var. tenuilextum, from the Trenton limestone ; E protetforme, from the 

 Trenton and Hudson river groups ; also, Gonioceras anceps, from the Black-river 

 limestone {Paleontology of New York, vol. 1). 



In 1850 Mr. Hall described Endoceras lativenlrum and Ormoceras remotlseptum, 

 from the Trenton limestone; and Colpoceras virgatum [= Endoceras virgatum], 

 from near the junction of the Birdseye and Black-river limestones. 



In 1 8 o 1 Mr. Hall described Huronia annulata, from the Niagara group {Report 

 on Lake Superior Land District: Foster & Whitney. 



In 1852 Mr. Hall described Orthoceras abruptum [—Cyrtoceras?] and 0. multi- 

 septum, from the Medina sandstone ; 0. virgulatum, from the Clinton and Niagara 

 groups; and 0. cancellatum [= 0. subcancellatum, H., 1877]; and identified 0. 

 imbricatum, Wahl., 0. annulatum ? Sow., 0. undulatum* His., and O. virgatum ? 

 Sow., from the Niagara group ; Ormoceras vertebratum and Discosorus conoideus, 

 from the Clinton group {Paleontology of New York, vol. 2). 



In 1857 Mr. E. Billings published the following species : Orthoceras cornuum, 

 from the Cbazy group ; 0. Allumetlense and 0. Minganense, from the Chazy and 

 Black- river groups; 0. decrescens, 0. hastatum, 0. Murrayi and 0. Ottawaense, from 

 the Black-river and Trenton groups ; 0. Hunmense, 0. Python, 0. vulgatum and 

 0. Xiphias, from the Trenton group ; 0. Anticostiense, 0. balteatum, 0. Lyelli, 0. 

 magnisulcatum, 0. propinquum, perannulalum, 0. Crocus and 0. Sedgwicki, from 

 the Hudson-river group ; 0. formosum, from the Trenton, Hudson-river and 

 Anticosti groups; O. rotulatum, from the Niagara group; O. persiphonatum and 

 0. Canadense (= Huronia vertebralis, Stokes, 1823), from the Middle Silurian; 

 and 0. Bucklandi, from the Upper Silurian {Rep. of Progr. Geol. Survey of Canada 

 for 1857). 



* The species annulatum and 0. undulatum are identical, the former having precedence in time. 



