127 



EuEYCHiLiNA Manitobensis, Ulrich. 



Eurychilina Manitobendx, XJlrich. .\8S9. Geol. Surv. Canada, Contr. Micro-Pal. 



Cambro-Silur. rocks, pt. 2, p. 53, pi. 9, figs. 

 10 and 10 a. 



Lower beds, Dr. R. W. Ells, 1875, one valve showing the exterior ; and 

 T. C. Weston, 1884, one valve showing the interior. 



Tetradella quadrilieata, var. simplex. 



Beyrichia qiiadrilirata, Hall & Whitfield . , 1875. Rep. Geol. Surv. Ohio, vol. II., pt. 



2, p. 105, pi. 4, figs. 6 and 7. 

 Strepida qiiadrilirata, Ulrich 1889. Geol. Surv. Canada, Contr. Micro 



Pal. Cambro-Silur. rocks, &c.; pt. 2. 



p. 54, pi. 9, fig. 12. 

 'J'ttraddla qiiadrilirata, \J\T\cix 1890. Journ. Cincinn. Soc. Kat. Hist. 



vol. XIII., p. 122. 

 " " 1894." Lower Silur. Ostrac. Minn. 



p. 679, pi. 46„figs. 1-11. 



Lower beds, T. C. Weston, 1884 : a single valve, the type of the variety 

 simjjlex, Ulrich. 



Tetradella lunatifera, Ulrich. 



Strepula lunatifera, Ulrich 1889. Geol. Surv. Canada, Contr. Micro-Pal. 



Cambro-Silur. rocks, &c., pt. 2, p. 56, pi. 9, figs. 



14 a-b. 

 Tetradella lunatifera, Ulrich. ,.1890. Journ. Cincinn. Soc. Nat. Hist., vol. XIII., 



p. 112. 

 " " " ...1894. Lower Silur. Ostrac. Minn., p. 680, figs. 



51 a-h, and pi. 46, figs. 12-14. 



Lower beds. Dr. R. W. Ells, 1875 : a single valve. 



On page 48 of the second part of the " Contributions to the Micro- 

 Palaaontology of the Cambro-Silurian rocks of Canada, published by this 

 Survey in 1889, a specimen from the lower beds, collected by Mr. Weston 

 in 1884, is referred by Mr. Ulrich to Bythocyjms cylindrica (Hall), but, 

 on page 688 of his memoir on the Lower Silurian Ostracoda of Minnesota, 

 published in 1894, Mr. Ulrich states that he is " now fully convinced " that 

 this identification is incorrect. 



