POSTGLACIAL BIOTA OF THE GREAT LAKES REGION 157 



Dr. Stearns 127 lists the following species from the "fossiliferous sands over- 

 lying the clays of Essex County, Ontario," associated with mastodon remains. 

 The deposits are probably referable to the Algonquin stage tho they might 

 belong to an earlier period. 



Valvata sincera Planorbis parvus 



" tricarinata " campanulatus 



Physq heterostropha Galba kumilis modicella 



Near Collingwood, Simcoe Distirct, on the Nottawassaga River, several 

 species of mollusks occur in sedimentory deposits, 128 which are probably refer- 

 able to the Algonquin stage, altho the section near Collingwood seems rather 

 low for this stage, but it is above the level of the Nipissing stage (632 feet). 129 

 The section near Nottawa seems referable to the Algonquin stage. Fossils 

 are reported as follows: 



North side of Pretty River, Nottawa, in deposit from 3 to 4}/£ feet beneath the surface. 



Polygyra albolabris Pyramidula alternata 



tridentata OmphaUna fuliginosa 

 " sayii (= say ana) 



Deposit near Collingwood, from surface to depth of three feet; height of section 78 feet 

 above the lake (659. 5 A.T.). 



Planorbis trivolvis Polygyra albolabris 



Goniobasis conica 13 " " tridentata 



livescens OmphaUna fuliginosa 



At the town of Angus, in Simcoe district, beds of lacustrine shells have been 

 observed which are probably referable to the Algonquin stage. 131 The town 

 of Colwell, not far distant, is on the Algonquin beach, which reaches a height of 

 774 feet, 132 and Angus is doubtless also situated on this beach. The species 

 recorded below are listed by Bell 133 and Coleman. 134 



Elliptio complanatus (very abundant) Planorbis antrosus ( = bicarinatus) 



Lampsilis luteola " campanulatus 



Sphaerium simile " trivolvis 



rhomboideum " deflectus 



Pisidium dubium ( = virginicum) " parvus 



" noveboracense Physa ancillaria 



Amnicola limosa Galba obrussa ( = desidiosa) 



" limosa porata " palustris 



137 Stearns, Nautilus, XIII, pp. 100-101. 

 M Geol. Can., p. 966; Dawson, Can. Nat., VI, pp. 49-50. 

 129 See Goldthwait, Geol. Surv. Can., Mem. No. 10, p. 24. 



13 ' It is difficult to surmise just what this species may have been. Conica is a synonym 

 of Pleurocera canaliculatum Say, a species not found in the northern part of the country. 



131 Hunter (Can. Geol. Surv., Rep. 1902, p. 290 A) refers these shells to the Nipissing stage. 



■ Goldthwait, op. cit., page 24. 



"• Geol. Can., page 966. 



1M Trans. Can. Inst., VI, p. 40. 



