365 



from this level, would indicate that this bed at least was 

 formed at a depth within the limits of wave action. 



In some places the succeeding beds are separated from 

 this by a thin layer of shale o • 4 inches ( 1 • cm.) thick. These 

 upper beds are similar to the lower five feet, but are darker, 

 not quite so fine grained, and are perhaps more fossiliferous. 



They are seen to better advantage in the next exposure 

 to the southwest, where a cliff about 20 feet (6 m.) above 

 lake level shows a total thickness of 12 or 13 feet (3 • 6 or 4 m) 

 above the fifteen inch (38 cm.) fossiliferous bed previously 

 mentioned. In a bed at the summit of the cliff, 11 feet 

 (3-3 m.) above this middle layer, are shown some of the 

 star shaped sponge spicules. 



Astreospongia hamiltonensis occurs abundantly in a single 

 bed of the limestone. 



Other fossils which have been collected here include the 

 following: — Cyathophyllum vermiculare var. praecursor, 

 Alveolites lallorum, A try pa reticularis, A try pa spinosa, 

 Cyrtina hamiltonensis, Paracyclas elliptica, Raphistoma 

 tyrrellii, Bellerophon pelops, Euomphalus subtrigonalis , 

 Omphalocirrus manitobensis, Hyolithes alatus, Gomphoceras 

 manitobensis , Cyrtoceras occidentale. 



The cliff mentioned appears, as seen from the lake, to be 

 a section across an anticline. On closer examination, it 

 appears to be a section through a dome some distance 

 beyond the centre. The apparent dips along the face, 

 which at either end bring the beds up from the shore level, 

 are but the components in this plane of the angles of dip 

 which would radiate from the centre of the dome. 



Below this cliff a great many of the blocks are from the 

 middle highly fossiliferous bed, which appears more 

 resistant than the other beds. On one of these blocks are 

 shown distinct curved wave marks, three crests and three 

 hollows, the distance from crest to crest being about 18 

 inches (45 cm.) and the depth of the hollow below the crest 

 about four inches (10 cm.). 



Farther to the south flat lying exposures are shown, one 

 at each end of the isthmus. They appear to be horizontal 

 and probably represent beds near the middle of the cliff 

 before mentioned. 



On the southern end of the island, just at the hatchery 

 dock, is the last rock outcrop. This dips comparatively 

 sharply towards the southwest, the angle of inclination 

 varying from 15 degrees to 30 degrees. In all a total 



