Dec, 1912.] Ordovieian Section, Lake Huron Area. 47 



which occurs eastward at greater intervals. It is the interval 

 between these two reefs which usually presents such a meager 

 fauna. Locally, however, for instance between Manitouaning 

 and Cape Smyth, the lower parts of this section appear richly 

 fossiliferous. 



Immediately above the Stromatocerium reef, at Kagawong and 

 Gore Bay, a rich pelecypod, gasteropod, and ostracod fauna, but 

 not consisting of many species, comes in. Among these, Ortonella 

 hainesi suggests the Whitewater age of the strata involved, while 

 Leperditia ccecigena and Primitia lativia are common at certain 

 horizons in the Saluda of Indiana but range to the top of the 

 Elkhom in Ohio. Cyrtodonta ponderosa, Ctenodonta iphigenia, a 

 large Archinacella, and various species of Lophospira occur. Among 

 the species which continue their range upward from below are 

 Strephochetus richmondensis, Tetradium huronensis, Hehertella 

 occidentalis, Zygospira modesta, Byssonychia radiata, and Pterinea 

 demissa. They are all fonns capable of continuing existence in 

 muddy waters, judging from the frequency with which they are 

 found in argillaceous limestones, fine grained sandstones, and 

 clays. The total thickness of this upper part of the Richmond, 

 from the Stromatocerium reef to the base of the Clinton, varies 

 apparently from 45 to 60 feet, on Manitoulin. 



E. QUEENSTOWN ShALES. 



The northwestern extension of the red clay shales, to which 

 the term Queenstown has been applied in the Niagara Falls area, 

 is well exposed on the Saugeen peninsula which separates Georgian 

 Bay from the main body of Lake Huron. In the vicinity of Colling- 

 wood, Meaford, Owen Sound, and westward, these red shales 

 evidently represent the strata above the Columnaria reef horizon 

 as exposed on Manitoulin. The only fossiliferous strata found in 

 these Queenstown shales, however, belong to those horizons above 

 the Stromatocerium reef in which ostracods are abundant. In 

 addition to Leperditia ccecigena and Primitia lativia, Eurychilina 

 striatomarginata and Drepanella canadensis are present, accom- 

 panied by the Richmond form of Bythocypris cylindrica, Byssony- 

 chia radiata, Pterinea demissa, a Zygospira resembling Z. ken- 

 tiickiensis, Bythopora delicatula, and other characteristic Ordo- 

 vieian fossils. 



At the Forks of the Credit, 65 miles southeast of Meaford, no 

 trace of this Richmond fauna was found anywhere in the Queens- 

 town red clay shale section. 



In the vicinity of Meaford, the highest layers of the Richmond 

 fauna occur fully 100 feet above the top of the richly fossihferous 

 Waynesville fauna at the base. The total thickness of the Queens- 

 town shales, in the vicinity of the Niagara Falls, however, is 

 estimated at 1000 feet, so that it may be only the basal part of the 

 Queenstown shale which is of Richmond age, although there appears 

 no lithological reason for imagining a different age for the upper 

 part of the Queenstown section. 



