80 



MuRCHisoNiA Xanthippe, Billings. 



Murchisonia Xanthippe, Billings. 1862. Geol. Surv. Canada, Pal. Foss., vol. I., 



p. 155, fig. 137. 



Gait, E. Billings, 1857 : a single and apparently slightly distorted 

 natural mould of the exterior of the shell. 



Murchisonia Vitellia, Billings. 



Murchisonia Vitellia, Billings. 1862. Geol. Surv. Canada, Pal. Foss, vol. I., p. 156, 

 fig. 138. 

 Nicholson. 1875. Rep. Pal. Prov., Ont., p. 3, fig. 6. 



Gait, E. Billings, 1857 : a natural mould of the exterior of the shell. 

 The woodcut of the type of this species is taken from a gutta-percha im- 

 pression of this mould. Elora, Professor H. A. Nicholson. Durham, 

 J. Townsend, 1883 : one fine large specimen with the test preserved. 

 The volutions in M. Vitellia are described by Mr. Billings as six in num- 

 ber, " strongly ventricose, obtusely angular, and with a flat spiral band 

 along the middle.'' 



B. Spire elongated, shell, slender : Murchisonia proper. 



BB. Volutions not more than twelve. 



Murchisonia Conradi, Hall. 



Murchisonia Conradi, Hall. 1867. Twentieth Rep. Reg.N. Y. St. Cab. Nat. Hist., p. 

 344, pi. 15 (6), fig. 19. 

 " Whiteaves. 1884. This volume, p. 27, pi. 4, fig. 6. 



The three specimens collected at Elora by Messrs. Weston and Boyle, 

 and referred to on page 27 of this volume as a local variety of M. Conradi, 

 are the only ones from the Guelph formation of Ontario that the writer 

 has seen. Professor Hall states that the shell of the typical form of this 

 species consists " of about seven volutions." 



Murchisonia Logani, Hall. 

 Murchisonia Logani, Hall. 1852. Pal. N. York, vol. II., p. 346, pi. 83, figs. 4, a-b. 



Gait, A. Murray, 1847, and E. Billings, 1857 ; Elora, R. Bell, 1861, 

 and T. C. Weston, 1867; Hespeler, T. C. Weston, 1867 ; and Fergus?, 

 teste E. Billings, in the " Geology of Canada." 



The surface markings of this species are still unknown, all the speci- 

 mens that have been collected so far being either coarse and imperfect 

 natural moulds of the exterior of the shell, upon which no remains of the 



