83 



concave, about two to the inch Avhere the diameter is thirty lines ; 

 siphuncle near the centre, small ; surface with from eight to ten annula- 

 tions in two inches. 



Of this species only three specimens have been collected in Canada. 

 The largest of these is 12 inches in length, 4 inches in diameter at the 

 larger, and 3 inches at the smaller extremity. It does not show any of the 

 septa. The second specimen tapers, from 42 lines to 34 lines in a length 

 of 9 inches. Some of the septa next the chamber of habitation are 

 obscurely visible. The third specimen, is a fragment showing seven septa 

 in a length of 42 lines. The annulations are somewhat variable in form 

 in the same specimen. Some are depressed convex or flat on the crest ; 

 others regularly convex, and still others have one edge abruptly elevated, 

 giving a sub-imbricated aspect. Township of Grimsby ; Niagara forma- 

 tion. J. Pettit. This species may be 0. imbricatum, Hall, Pal. N. Y., 

 vol. ii, not 0. imbricatum Sowerby. 



0. Cadmus, n. sp. — This species appears to attain a length of two or 

 three feet with a diameter of three or four inches at the aperture. 

 Section circular, or nearly so ; septa from two to three in an inch ; 

 siphuncle nearly central, cylindrical, slightly constricted in the passage 

 through the septa, from two to three lines in diameter. The rate of 

 tapering appears to vary from about 1 line to I2 lines to the inch. The 

 chamber of habitation is 6 inches in depth, where the diameter of the 

 aperture is 3 inches. In some specimens the aperture is slightly con- 

 stricted. The shell varies in its characters. On the septate portion it is 

 longitudinally fluted with concave furrows, separated by sharp-edged 

 ridges ; width of the furrows in a specimen 16 lines in diameter, 2 lines ; 

 where the diameter is 2 inches from 2J to 3 lines. The furrows are often 

 divided by a small elevated line along the middle. There are from 6 to 8 

 fine transverse engirdling strijB in the length of 2 lines. Longitudinal 

 striae are also visible, but they are not so distinct as the transverse. In 

 specimens denuded of the shell there are only obscure indications of the 

 longitudinal fluting. The chamber of habitation has numbers of wide 

 shallow annulations with no indications of furrows on the cast, but these 

 are seen on the shell in one specimen near the bottom of the chamber. 

 It occurs in the township of Grimsby ; Niagara formation. J. Pettit. 

 This species appears to be 0. cancellatum, Hall, not 0. eancella- 

 tum Eichwald. 0. annulatum, Sowerby.=(0. undulatum, Hall Pal. 

 N. Y. vol. 2.) occurs along with it. 



O. Brontes, n. sp. — Two or three feet in length ; three or four inches 

 in diameter at the aperture ; section circular ; tapering at the rate of 

 about li lines to the inch ; septa from moderately to rather strongly con- 

 cave, from five to eight in the length of two inches ; siphuncle central or 



