126 



Apaechites minutissimus, Hall. (Sp.) 



Leperditia(Isochilina)minutissima,'H.a,U 1871. Desor. New. Spec. 



Foss. Hudson R. Gr. , &c., 

 p. 7. 



" 1872. 24th Reg. Rep. N. Y. 



St. Cab. Nat. Hist., p. 231, 

 pi., 8, fig. 13. 

 Hall & Whitfield.. 1875. Rep. Geol. Surv. 

 Ohio, vol. II., pt. 2, p. 102, 

 pi. 4, fig. 4. 



Aparchites minutissimiis, Ulrich 1889. Geol. Surv. Canada, , 



Contr. Micro-Pal. Cambro- 

 Silur. rocks, &c., pt. 2, p. 49. 



Lower beds, Dr. R. W. Ells, 1875 : the right valve figured by Mr. 

 Ulrich. 



Primitiella unicornis, Ulrich. 



Leperditia unicornis, Ulrich. ..1879. .Tourn. Cinoinn. Soc. Nat. Hist., vol. II., p. 10, 



pi. 7, fig. 4. 

 Aparchitex unicornis, Ulrich , . 1889. Geol. Surv. Canada, Contr. Micro-Pal. Cambro- 



Silur. rocks, &;c., pt. 2, p. 50, pi. 9, fig. 11. 

 PWmi^ieHa mwcorjMS, Ulrich, .1894. Lower Silur. Ostrac. Minn., p. 649, pi. 43, 



figs. 75-77. 



Lower beds, the single valve referred to in Mr. Ulrich's Report pub- 

 lished by this Survey. 



Peimitia lativia, Ulrich. 



Pn'mtita toiri'a, Ulrich, .1889. Geol. Surv. Canada, Contr. Micro-Pal. Canibro- 

 Silur. rocks, &o., pt. 2, p, 50, pi. 9, figs. 8 and 8 a. 



Lower beds, R. W. Ells, 1875, and T. C. Weston, 1884 ; several single 

 valves. 



Primitia (?) (? Beyeichia) parallela, Ulrich. 



Primitia ? (? Be.yrirhia) parallela, Ulrich , , 1889. Geol. Surv. Canada, Contr. Micro- 

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

 51, pi. 9, figs. 7 and la. 



Lower beds, T. C. Weston, 1884 : two imperfect valves. 



