340 THE DEVONIAN FOSSILS OF CANADA WEST. 
appeared in the lower Silurian seas, and is found more or tess 
abundantly in-every formation from the Chazy up to the Chemung 
group. Many of the Devonian specimens so exactly resemble some 
‘of the varieties of S. alternata, the dominant species of the Trenton 
and Hudson River group, that were it not for the striated area and 
nearly obsolete foramen, they could not be separated therefrom. The 
general form, striation of the surface, and some of the internal mark- 
ings are so nearly the same, that one can scarcely help thinking that 
those we find in the Devonian rocks are the lineal descendants of 
those with which the lower Silurian strata are crowded. Professor 
Hall’s description of S. varistriata of the Lower Helderberg rocks, 
of New York, applies exactly to this species (See Pal. N. Y., Vol. 3, 
p- 180-184) the only difference being that the specimens are in 
general smaller. I think that on comparison of good series of speci- 
mens that species may yet be united to this, or perhaps all those above 
‘cited may be united under one name S. varistriata. Should only the 
Devonian varieties be united I think they should all be referred to 
S. inequistriata, as that form has been more extensively described 
and illustrated by Conrad and Hall than any of the others. 
Locality and formation.-—Oriskany Sandstone ; Corniferous Lime- 
stone; and Hamilton Group at nearly all the localities of these rocks 
in Canada West. 
Collectors —A. Murray; J. Richardson; J. De Cew; E. De Cew; 
Wm. Saunders, London, and Judge Wells, Chatham. 
STROPHOMENA Patersont ?—(Hall.) 
StropHomena Parersonia.—Hall. Tenth Annual Report of the 
Regents of the University of New York. 
Fig. 115. 
Fig. 115. Strophomena Patersoni Ventral view. 
