81 



slit band or lines of growth are preserved, with the corresponding cast of 

 the interior in place, or separate casts. All that appears to be known of 

 the shell is, that it is elongate, turreted and composed of about eleven 

 rounded ventricose volutions, that are much broader than high. 



MUECHISONIA MACEOSPIRA, Hall 



Murchisonia macrospira, Hall 1852. Pal. New York, Vol. II., p. 346, pi. 83, 



fig. 5. 

 Billings.... 1863. Geol. Canada, p. 339, fig. 334. 

 Nicholson.. 1875. Rep. Pal. Prov. Ont., p. 70, pi. 3, fig. 9. 

 Whiteaves , 1884. This volume, p. 27, pi. 4, fig. 7 and 7a.. 



Gait, A. Murray, 1845, and E. Billings, 1857 ; Elora, D. Boyle, 1880. 

 The species has also been collected at Durham by Mr. Townsend, and at 

 Belwood (in 1893) by Mr. Townsend and the writer. With the excep- 

 tion of the one from Elora represented on Plate 4, fig. 7a, of the present 

 volume, all the specimens of this species that the writer has seen are 

 natural moulds of the exterior of the shell. The type of M. macrospira, as 

 figured by Professor Hall, is a mould of the exterior of five of the later 

 volutions. A gutta-percha impression of this mould has recently been 

 presented to the Museum of the Survey by Professor R. P. Whitfield. 

 It shows that the volutions are rounded, ventricose and encircled at their 

 mid-height by a low, rounded, spiral ridge which represents the slit band. 

 Other specimens shew that the number of volutions is at least nine. 



It is very doubtful whether the distinction between this species and 

 M. Logani can be be sustained. The original figures of both give the 

 impression that the volutions of M. Logani are a little broader in pro- 

 portion to their height and perhaps slightly more numerous than those of 

 M. macrospira, but these apparent difierences do not seem to hold good 

 when a series of specimens is compared. In the diagrammatic figure of 

 M. m,acrospira on page 339 of the " Geology of Canada," the volutions 

 are more like those of M. Logani than those of M. macrospira. Again, 

 the writer can see no difference, except in size, between the specimen 

 which Professor Nicholson figures on Plate 3, fig. 4, of his second "Re 

 port upon the Palseontology of the Province of Ontario " as M. Logani, 

 and that which he figures on the same Plate, figure '9, as M. macrospira. 



MuECHisoNiA BoYLEi, Nicholson. 

 Murchisonia Boylei, Nicholson . 1875. Rep. Pal. Prov. Ont., p. 71, pi. 3, fig 1. 



Elora, D. Boyle : a natural mould of the exterior of the shell, which is 

 stated by Professor Nicholson to have been presented to the Museum of 



