90 



Gait, Professor James Hall, 1848 ; Hespeler, T. C. Weston, 1871 ; 

 Durham, J. Townsend, 1878-82; Elora, J. Townsend, 1892 and 1893; 

 and Belwood, J. Townsend and J. F. Whiteaves, 1893. 



The original types of this species, as figured by Hall, are three in 

 number, viz., (1) an imperfect cast of the interior of the shell, with part 

 of the exfoliated test preserved on the lower half of the outer volution ; 

 (2) "a small individual" about nine millimetres in height; and (3) "an 

 impression of" the "base of the shell in limestone.'' These give a very 

 imperfect idea of the shape of the shell, and none whatever of the surface 

 markings of the spire and upper portion of the outer volution. The 

 woodcuts of C. sulcata in the "Geology of Canada" are mere reproduc- 

 tions of two of Hall's figures of that species, and the specimen from Dur- 

 ham referred to and illustrated in the first part of this volume, does not 

 add much to our knowledge of its characters. 



The specimens recently collected at Elora by Mr. Townsend are two in 

 number. Both of these have nearly the whole of the test preserved, and 

 one of them has also a small portion of its operculum still remaining 

 almost in situ, but turned inside out. So much of this operculum is 

 broken off that it is impossible to say whether it was originally solid or 

 hollow inside, but there is enough left to show that it is calcareous, multi- 

 spiral and not much elevated exteriorly. 



The specimens collected at Belwood by Mr. Townsend and the writer, 

 are sharply defined natural moulds of the exterior of four dififerent shells, 

 and gutta-percha impressions of these moulds, such as the one figured in 

 Plate 13, together with the two testiferous examples from Elora, give the 

 following new information about the species. A specimen of average size 

 is about thirty millimetres in height, and twenty-five in maximum 

 breadth. The volutions are five or six in number, rounded and ventri- 

 cose, but depressed and fiattened above in such a way as to form a 

 shoulder with a narrow band between it and the suture. In the centre 

 of the base of the outer volution there is a narrow but rather deep um- 

 bilicil depression, but no portion of any of the inner volutions is ex- 

 posed. The upper portion of each of the last three volutions is marked 

 by a few spiral raised lines, and their central and lower portions are en- 

 circled by narrow ridges. Upon the lower half of the last volution of 

 the spire of the specimen figured there are four spiral ridges, and upon 

 the central and basal portions of the outer volution of another specimen 

 there are as many as ten or eleven spiral ridges, the three around the um- 

 bilical depression being more prominent and distant than any of the 

 others. The volutions, also, are everywhere crossed by crowded and 

 oblique minute raised lines. 



