82 



Toronto University. The shell, as represented by a gutta-percha impres- 

 sion of this mould, is described as " turreted, with a long conical spire, 

 the apical angle of which is about 18°". Its volutions are said to be "ten 

 or eleven in number, increasing regularly from the apex to the mouth, 

 flat, with a well marked spiral band or angulation situated just above the 

 suture," which causes " the lower part of each whorl to project over the 

 upper portion of the whorl next below." The suture is represented as 

 " canaliculated," the body whorl as little larger than the preceding one, 

 and not ventricose, and the base as " somewhat produced below, appar- 

 ently with a small umbilicus. 



The writer has never seen a specimen of M. Boylei, but it appears to 

 be a well characterized and distinct species. 



MuRCHisoNiA CONSTRICTA, Whiteaves. 



Murchisonia constricta, Whiteaves. .1884. This volume, p. 85, pi. 4, fig. 4. 



Durham, J. Townsend : a single specimen. Perhaps a variet}' of the 

 preceding species. 



MUECHISONIA BIVITTATA, Hall. 



Plate 12, figs. 5 and 6. 



Murchisonia bivittata, Hail 1852. Pal. N. York, vol. II., p. 345, pi. 83, 



figs. 1, a-b. 

 " " Nicholson .. 1875. Rep. Pal. Prov. Ont., p. 70, pi. 3, fig. 7, 



but not fig. 8. 



Gait, A. Murray, 1847, and E. Billings, 1857 ; Hespeler, T. C. "Weston, 

 1867 and 1871; Elora and Hespeler, Professor H. A. Nicholson; Bel- 

 wood, J. Townsend, 1892, and J. Townsend and J. F. Whiteaves, 1893. 



This is one of the commonest fossils of the Guelph formation at these 

 localities, and one that, as has been pointed out by Professors Hall and 

 Nicholson, is most readily recognized by the " double spiral fold or carina" 

 upon its columella. The condition in which M. hivittata is usually ob- 

 tained, is either that of natural longitudinal sections of the hollow shell, 

 with the columella preserved throughout and the broken edges of the 

 test exposed ; or casts of the interior, or specimens with the outer layer 

 of the test exfoliated. When perfect the shell was evidently composed of 

 two layers of about equal thickness, but no considerable portion of the 

 outer surface of the test is preserved in any specimen that the writer has 

 seen. 



Specimens of this species recently collected at Belwood by Mr. Towns- 

 end and the writer, give the following additional information about the 



