58 



GEOIvOGY OF lyA SAIvIvE COUNTY. 



if not quite, equal to the Mazon locality in the number 

 and beauty of their specimens. The shale is un- 

 derlaid by a hard, blue limestone, which, where ex- 

 posed weathers to buif, the surface of which lies 

 in reg"ular waves, the distance between crests being* 

 about a rod. It is usually divided into blocks by 

 almost imperceptible seams or cracks. It is from 

 fifteen to eig'hteen inches thick. A stratum of cone in 

 cone from four to eig'ht inches thick is found in the 

 coal measures almost everywhere. It occurs in the 

 north bluff west of Ottawa, on Brewery Hill, and else- 

 w^here, and at about the same level. 



For coal measure fossils exclusive of ferns La 

 Salle and vicinity is the best collecting- ground. For 

 several species of small but finely preserved shells the 

 black slate in a ravine back of the old Caton Deer Park 

 is one of the best localities we have tried. The same 

 slate is found in several ravines east of the Caton 

 place, but not far to the west of it. Several localities 

 on Covell creek, several on the Big* Vermillion, near the 

 south end of the bridg-e, Marseilles, are all rich in 

 fossils. 



Mr. W. W. Calkins sug*g*ests a careful examina- 

 tion of the strata about Bailey's falls. We would also 

 direct attention to the shales bordering most of the 

 streams in Deer Park and Farm Ridg*e Townships 

 in their lower courses as worthy of much more careful 

 study than they have yet received. We found in these, 

 on the premises of Hon. Urbin Kllsworth, a fine 

 shark's tooth, when not looking* for fossils. A system- 

 atic search oug-ht to find others. 



Additional Notes. — On the north bluff oppo- 

 site Buffalo Rock, where the road descends the bluff 

 the surface of the St. Peters is traversed by many veins 



