POSTGLACIAL BIOTA OF THE GREAT LAKES REGION 159 



In Hamilton, just west of the Catholic cemetery, bordering the Dundas 

 marsh, a bed of shell marl occurs, which is about 15 feet in thickness. As the 

 mollusks are all land species they may belong to a later period. Four species 

 are listed." 



Polygyra albolabris Pyramidula alternata 



" tridentata Succinea obliqua 



Near Toronto several localities exhibit good exposures of the Iroquois 

 beach. 141 From street cuttings in the sandy plain east of the Don River, four 

 mollusks were obtained. 



Elliptio complanatiis Galba palustris? 



Planorbis campanulatus (in error complanatiis) Succinea avara 



From Reservoir Park a number of specimens, more or less perfect, were 

 secured. 



Unios, several species, worn Pleurocera, several species 



Sphaerlum, Campeloma decisum 



From the Carlton sand and gravel pit, 12 to 20 feet below the surface, in 

 a gravel and on a clay deposit at the base of the gravel, the cast horns of a bar- 

 ren ground caribou were found. Other specimens have been found in the vi- 

 cinity. From a gravel deposit at York a mammoth tooth was taken. 



Near the Don River above Taylor's first paper mill a well was drilled on the 

 hillside, 35 feet below the level of the Iroquois beach. The drill penetrated 

 38 feet of sand and gravel, often cemented by carbonate of lime; shells were 

 encountered 70 feet below the level of the Iroquois beach. The sand deposit 

 rests upon the surface of weathered peaty clay, which is thot to be interglacial. 

 This weathered zone may represent a low-water stage and the mollusks may 

 have been buried during the rise of the water. The mollusks found belong 

 to the genera Unio, Sphaerium and Pleurocera. 



Ami 142 enumerates the following species from the gravel pits of west Toron- 

 to, referring them to the Lake Warren episode. Coleman refers all post- 

 Glacial deposits to the Iroquois Stage. 143 



Lampsilis luleola Goniobasis livescens 



Sphaerium rhotnboideum Physa ancillaria 



Pisidium abdilum Planorbis campanulatus 



" noveboracense " bicarinatus ( = anlrosus) 



Valvata sincera " deflectus 



" tricarinata " parvus 



"•See Coleman and Spencer, Trans. Can. Inst., VI, p. 29; Can. Nat., N. S., VII, p. 

 470; X, p. 308. 



141 Coleman, op. cit., pp. 37-39. 



142 Trans. Roy. Soc. Can., (ii), VI, part iv, p. 153. 

 "» Bull. Geol. Soc. Amer., XIV, pp. 347-368. • 



