14 The Ottawa Naturalist. [April 



Liiuites, as now restricted, nor even to the Family Lituitidae. This 

 fossil was referred to Tfocholiies by the writer in 1884, and to 

 Discoceras, Barrande, by Hyatt in 1894, who, however, admits 

 the " close connection " between these two genera, and, in his 

 latest publication,* includes both of them in his Family Trocho- 

 litidae. It is still perhaps doubtful whether this Guelph species is 

 a Trocholites or a Discoceras, but in the Cambro-Silurian rocks of 

 Quebec and Ontario there are now known to be at least three un- 

 doubted and well marked species of Trocholites, upon which the 

 following- notes are submitted. 



Trocholites ammonius, Conrad. 



Trocholites ammonius, Conrad. 1838. Second Ann. Geol. Rep. St. N. York, 



p. 119. 



,, ,, Emmons. 1842. Geol. New York, pt. Ii, p. 279, fig-. 3; 



and p. 392, fig. I. 

 Utica trocholite , Vanuxem. 1842. Geol. New York, pt. ni, p. 57, fig. 3. 

 Trocholites ammonius, Hall. 1847. Pal. New York, vol. i, p. 192, pi. XL, A, 



figs. 4, a—k. 



,, ,, Emmons. 1855. Amer. Geology, p. 146, fig. 29, and 



pi. XII, figs. 14, a — d, and 15. 



., ,, Ami. 1888. Canad. Rec. Sc, vol. in, no. 2, p. 105. 



,, ,, Foord. 1891. Cat. Foss. Cephal. Brit. Mus., pt. 11, 



P- 47- 

 ,, ,, Hyatt. 1804. Phylogeny of an Acquired Characteristic, 



in Proc. Amer. Phil, Soc , vol. xxxii, no. 143, p. 486. 



This species, which is the type of the genus, seems to be well 

 characterized by its •■' very peculiar, rough, fretted surface" or 

 *' cuticular corrugations," that have been minutely described by 

 Hall and Hyatt. Hall says that " this shell Oj:cupies a central 

 position in the Trenton limestone " (of the State of New York) 

 " being unknown in the lower part, but passing upwards into the 

 Utica slate, where it is of less frequent occurrence." 



So far, in Canada, T. ammonius has been found only in the 

 Utica slate or shale. In 1878, Mr. Walter R. Billings showed the 



* The article Cephalopoda in Eastman's translation of Ziltel's Text-book 

 of Palseontology. 



