8o 



of the Richmond and continue apparently into the Liberty, 

 but the bryozoans, submitted to Dr. E. O. Ulrich, indicate 

 a Bellevue or middle Maysville age, rather than a lower 

 Richmond horizon. 



Lower Richmond. — Capt Symth, at the northeastern 

 corner of Manitoulin island, has long been known as a type 

 locality for various Richmond fossils, but it is rarely visited 

 by the geologist. This is due to the expense and the 

 inconvenience attending a hasty visit in the absence of a 

 camping outfit. Four miles south of Cape Smyth, the 

 steep white Clay Cliffs rise to a height of over 200 feet 

 (60 m.) above the level of the lake. 



As frequently happens with such steep exposures, 

 more than half of the slope of the cliff is cove ed w th 

 talus, and only along the upper half of the cliff are the 

 strata directly accessible. A Stromatocerium reef occurs 

 30 feet (9-1 m.) below the top of the cliff, and the over- 

 lying limestone strata present such a steep front as to 

 be almost inaccessible. Herbertella inscuplta, (Hall), 

 a form which demarcates the base of what here is included 

 in the Lower Richmond, has a vertical range of about 

 10 feet (3 m.) at a horizon 30 feet (9-im.) below the 

 Stromatoceruim reef. The total thickness of the Lower 

 Richmond at this locality, therefore, is about 40 feet 

 (12-2 m.) . 



The following fossils occur in the strata below the 

 Stromatocerium reef but are not known above it — 



Protarea richmondmsis papillata Foerste. 

 Constellaria polystomella, Nicholson. 

 Rhombotrypa quadrata ( Rominger). 

 Catazyga headi (Billings.) 

 Crania scabiosa Hall 

 Hebertella insculpta Hall. 

 Platystrophia clarksvillensis Foerste. 

 Plectambonites sericeusf Sowerby ) (small variety). 

 Rafinesquina alternata (Emmons) (very flat 



form) . 

 Strophomena huronensis Foerste. 

 Strophomena neglecta James. 

 Strophomena nutans Meek. 

 Strophomena planumbona Hall (S. rugosa Blain- 



ville.) 

 Cyclonema bilix Conrad. 



