56 



Trimerella Dalli, Davidson and King. 



rWmereMa DaKJ, Davidson & King. .1874. Quart. Journ. Geol. Soc, Lond., vol. 



XXX., p. 154, pi. 15, figs. 1-3. 

 " " Nicholson 1875. Rep. Pal. Prov. Out., p. 68. 



Hespeler, T. C. Weston, 1867 : several casts of the interior of the shell. 

 Elora and Hespeler, Professor H. A. Nicholson. ^ 



MONOMERELLA PRISCA, BillingS. 



Monomerella prisca, Billings 1871. Can. Nat., vol. VI., ser. 2, p. 221. 



" " Davidson & King. .1874. Quart. Journ. Geol. Soc. Lend., vol. 



XXX., p. 156, pi. 17, figs. 5-8. 



" Nicholson 1875. Rep. Pal. Prov. Ont., p. 68, fig. 38. 



" Hall 1892. Pal. N. York, vol. VIII., pt. 1, 



p. 41, pi. 4C, figs. 6-13. 



The types of this species and all the specimens of it referred to by 

 Messrs. Davidson and King in their paper on the Trimerellidse were 

 GoUected at Hespeler by Mr. Weston in the spring of 1871. Professor 

 Nicholson (op. cit.) records it as occurring also at Elora. All the speci- 

 mens of M. prisca and M. orbicularis that have yet been obtained are 

 mere casts, in dolomite, of the interior of the shell. 



Monomerella oebicdlaris, Billings. 



Monomerella orbicidaris, Billings 1871. Can. Nat. , vol. VI., ser. 2, p. 221. 



" " Davidson & King .. 1874. Quart. Journ. Geol. Soc. Lond., 



vol. XXX., p. 158, pi. 17, fig. 10. 



Elora, T. C. Weston, 1867 ; five casts of the interior of the shell : 

 Durham, J. Townsend ; a similar specimen. 



Monomerella ovata, Whiteaves. 



Monomerella ovata, Whiteaves. 1884. This vol. pt. 1, p. 5, pis. 2, figs. 1, and 8, 



figs. 1, 1, a-c. 



" Hall 1892. Pal. N. York, vol. VIII., pt. 1, pi. 4D, figs. 



13-15. 



Durham, J. Townsend, 1875-82 : one perfect specimen, with the valves 

 slightly displaced, and four separate pedicle valves. 



Monomerella ovata, var. lata. 



Monomerella ovata, var. lata, Whiteaves. 1884. This vol., pt. 1, p. 6, pis. 2, figs. 2 



and 2a, and 8, figs. 2 and 2a. 



" " Hall 1892. Pal. N.York, vol. VIII., pt. 1, 



pis. 4C, figs. 17-18, and 4D, figs. 11 

 and 12. 



