GLACIAL AND INTERGLACIAL BEDS 29 1 



added however that no fossils have been obtained from the 

 uppermost three feet of brown sand. The lower section differs 

 slightly in fauna from the upper one, containing numerous 

 anodons and campelomas, which are almost absent from the 

 beds at the brickyard ; but the unios and trees are alike. 



In previous papers the warm climate beds have been repre- 

 sented as ending just beneath the peaty blue clay (No. 7) which 

 was considered to belong to the cool climate beds, chiefly 

 because it contained peaty layers and had yielded a shed horn 

 of caribou. Recently, however, the peat has been examined and 

 found to contain no mica scales and very few mosses or spruce 

 needles, which are very characteristic of the peaty layers 

 belonging to clays of the cool climate. Instead of this the 

 brown layers consist mainly of fragments of deciduous leaves. 

 The recent finding of unios at the top of the blue clay strengthens 

 the opinion that it and the brown sand above should be included 

 with the warm climate beds. The lowest point at which the 

 unio clays and sands have been found is 41 feet below Lake 

 Ontario at the foot of Scarboro' Heights, giving a vertical range 

 of more than 100 feet for the whole series of warm climate beds 

 The following species have been obtained in the Don beds : 



FAUNA OF WARM CLIMATE BEDS, DON VALLEY 

 Vertebrata : possibly mammoth or mastodon and bison, and an undetermined 



fish. 

 Arthropoda : several undetermined beetles and cyprids. 

 Mollusc a : 



Unio undulatus 

 " rectus 

 " luteolus 

 " gibbosus J 

 " phaseolus ^ 



\ still living in Lake Ontario. 



i 



pustulosus ! still living in Lake Erie, but not reported from 

 trigonus Lake Ontario. 



coccineus 



J 



occidens 



solidus I not known in the St. Lawrence system of waters, 



clavus but living farther south, 



pyramidata J 



