1904] The Canadian Species of Trocholites. 15 



writer specimens of it, that he (Mr. Billing-s) had recently found 

 in the Government House grounds at Ottawa. But, it was not 

 until ten years after this that Dr. H. M. Ami recorded the dis- 

 covery and recognition of the species in Canada ; at Ottawa in 

 the second volume of this journal, and at Murray Bay, Whitby 

 and Collingwood in the third volume of the "Canadian Record of 

 Science." 



Trocholites planorbtformis, Conrad. 



Trocholites planorbtformis, Conrad. 1842. Journ. Acad. Nat, Sci. Philad,, 



vol. VIII, pt. 2, p. 274, pi. XVII, fig. I. 



,, ,, • Hall. 1847. P^'- New York, vol. i, p. 310, 



pi. LXXXIV, fig-s. 3, a — /. 



"Volutions higher than wide, longitudinally striated, and 

 with oblique obtuse, transverse lines, approaching at an angle but 

 rounded on the centre of the back ; apex profoundly depressed ; 

 back of the large volution flattened ; aperture much longer than 

 wide. Locality. Near Grimsby, Upper Canada, in Salmon River 

 sandstone. This elegant shell was tound in a boulder, by Mr. S. 

 Ashmead, of this city" (Philadelphia) " and by him presented to 

 tha Academy of Natural Sciences. A specimen was kindly given 

 me by this liberal and enterprising mineralogist " (Conrad. In 

 addition to this. Hall says that the surface of this species is 

 "marked by obliquely transverse ridges, which bend backwards, 

 forming a broad curve on the dorsal line, longitudinally striated 

 with rounded lines." And, in specimens of T. atnmoniusy from 

 the Trenton limestone, he says that he has "rarely found the 

 transverse and longitudinal ridges so strongly marked." 



So far as the writer is aware, no other specimens of T. planor- 

 biformis than the two types from Grimsby have been found in Can- 

 ada, as the fossils from Montmorenci or Montmorency Falls and 

 Lorette that Dr. Foord identified with that species in 1891, prove 

 to be referable to the since described T. Canadensis, Hyatt. 



Hall, in 1847, describes T. planorbiformis as one of the fossils 

 of the Hudson River (Lorraine) formation of the State of New 

 York, and his successor. Dr. John M. Clarke, in 1903, in his 

 "Classification of the New York series of geological formations," 



