WHITEAVE8.] FOSSILS OF HAMILTON F0R3IATI0N OF ONTARIO. 115 



the Hamilton Group" in Iowa and Illinois. In Professor Hall's species, 

 however, the entire surface of the valves is represented as granulose, 

 whereas in the S. suhdecussata, in addition to the concentric lines of 

 gi-owth which are common to all brachiopodous shells, the ribs on the 

 lateral areas are marked by exceedingly tine and crowded radiating 

 lines, which are scarcely visible to the naked eye, and no traces of 

 granulations caa be detected, or have yet been detected, on any por- 

 tion of its surface. 



XUCLEOSPIRA CONCINNA, Hall. 



Atrypa concinna, Hall. 1843. Geol. Rep. Fourth Distr. X. York, p. 200, fig. 3. 

 Nwleospira concinna, Hall. 18.59. Twelfth Rep. X. lYork St. Cab. Nat. Hist., 



pp. 2.5 and 26. 

 " 18,57. Pal. State N. York, vol. IV., pt. 1, 279, pi. 



45,figs. 33-57. 



Xear Thedfoi-d, Eev. J. M. Goodwillie, 1882 : nine good specimens. 



Meristella unisulcata, Conrad. 



Atrypa unigidcata, Conrad. 1841. Ann. Rep. Pal. N. York, p. 56. 



Rhynchonella unisv2cata, HalL 1857. Tenth R«p. N. York St. Cab. Nat. Hist., p. 125. 



Aihyris (?) unimlcata, Billings (as of Conrad). 1860. Canadian Journal, pi. 32, 



figs. 39^2. 

 MeriskUa unimlcata, Hall. 1867. Pal. State N. York, vol. lY., pt. 1, p. 309, pi. 50, 



figs. 18, 35. 



Township of Bosanquet, Mr. J. Pettit, 1868 : two ventral valves ; and 

 near Thedford, Eev. J. M. Goodwillie, 1882 : one specimen with both 

 valves preserved. The species has previously been recorded from the 

 Corniferous Limestone of Ontario, but the specimens indicated above 

 are the only ones that the writer has seen from the Hamilton Group 

 of that province. 



Meristella Haskinsi, Hall. 



Meristella Haskinsi, Hall. I860. Thirteenth Rep. N. York St. Cab. Nat. Hist., p. 84. 

 « " " 1867. Pal. State N. York, vol. VI., pt. l,p. 306, pi. 49, 



flgs. 23, 35. 



Near Thedford, Eev. J. M. Goodwillie, 1882 : one specimen which is 

 nearly perfect, but which has most of the outer and part of the inner 

 layer of the test exfoliated. 



