American Association. §67 



cf our kiusmeu is, ^yitll certain modifications, the same as iu the 

 ancient realm of Caractacus. 



Excuse this hurried letter, and wishing you as successful a meet- 

 ing as your labors and those of my other eminent friends in the 

 United States deserve, 



Believe me to be. 



Yours very sincerely, 



RODERICK I. MURCHISON. 

 To Sir W. LoaAN. 



NOTE ON" THE FOSSILS BY J. W. SALTER, F.G.S. 



The specimens previously sent from Durness were far from 

 satisfactory, and though clearly Palaeozoic, could not be appealed 

 to as settling their true place. They might, indeed, have been 

 either Carboniferous or Devonian, although Sir R. Murchison had 

 offered strong geological reasons to lead us to suppose them to be 

 Lower Silurian forms. One cast in particular, which was at first 

 doubtfully regarded as a Maclurea, though it had a right-handed 

 curvature of the whorls, is now more properly referred to Raphis- 

 toma or Ophileta. And an Orthoceras present in the same beds 

 could not decide the case. But those lately collected by Mr. 

 Peach leave no doubt as to the true age of the beds. The prin- 

 cipal fossil will be particularly interesting to Canadian geologists 

 — being the same as one from the " Calciferous Sandrock" of 

 Beauharnois, and which, being undescribed, has received the MSS 

 name of Ophileta compacta. The genus is doubtful, and the fossil 

 is probably only a sub-genus of i2a^/i^stow^a (Hall) — the species of 

 which have a wide umbilicus (bounded by a very prominent ridge) 

 and straight-sided whorls. This species in Canada grew full an 

 inch and a half wide, and had as many as six or seven whorls, flat 

 above, and with a sunt, apex, and a very broad and wide umbilicus, 

 so that the entire shell is much attenuated, and the inner whorls 

 would easily break out, as in Mr. Halls's figure of 0. levata, Pal. 

 4, Y ; PI. 3, vol. 1, fig 4. The whorls of that species are much 

 less carinate below, and the umbilicus not nearly so wide. O. 

 compacta will be fully figured and described in a decade of 

 the Canadian fossils — it is unnecessary to say more of it here. It 

 is curious that the EuompTialiis (^Maclurea matutina) which ac- 

 companies the Beauharnois fossil in Canada, is found also in the 

 Highland beds, with another thick whorled species. Again, a 



