132 



The Canadian Field-Naturalist 



[Vol. XXXVI 



A LIST OF SHELLS FROM GODERICH, ONTARIO. 



By Bryant Walker 



IN the summer of 1921 Mr. A. W. Andrews, 

 the well-known coleopterist of Detroit, 

 Mich., spent his vacation at Goderich and 

 very kindly collected for me such shells as he 

 came across while in the field. 



The list, although not large, is of interest as it 

 includes at least one form not hitherto recognized 

 in Canada and extends the range of several others 

 very considerably towards the west and seems 

 worthy of preservation as a local list. 

 Polygyra albolabris (Say). 



Ten fully matured specimens are all rather thin 

 and noticeably greenish in tinge. They vary in 

 height from 16 to 21.20mm. with an average of 

 18.18 mm. and in diameter from 23.75 to 29 mm. 

 with an average of 26.7 mm. The axial index 

 varies from .641 to .859 with an average of .684. 



A comparison of the average shell of this series 

 with the average shells from the Upper and Lower 

 Peninsulas of Michigan and the Charity Islands, 

 Lake Huron, (Walker, Occ. Pap., Mus. Zool., 

 Univ. Mich., No. 7, 1915, p. 2) may be made as 

 follows: 



Axial 



Locality Height Diameter Index 



Upper Peninsula 17 . 02 25 . 81 .654 



Lower Peninsula 18.10 27.10 .677 



Charity Islands 18.51 26 . 33 .704 



Goderich 18.18 26.70 .684 



This shows the Goderich shells to be larger in 

 diameter than those from the Upper Peninsula 

 and the Charity Islands and smaller than those 

 from the Lower Peninsula; but higher than those 

 from the Upper and Lower Peninsulas and lower 

 than those from the Charity Islands. 



Polygyra thyroidus (Say). 



Rather small, varying from 21 to 22 mm. in 

 diameter and like the preceding species decidedly 

 tinged with green. 



Polygyra tridentata (Say). 



Rather small, varying from 12 to 14 mm. in 

 diameter and quite depressed. 



Polygyra monodon (Rack). 



fraterna (Say). 



Pyramidula alternata (Say). 



" cronkheitei anthonyi Pils. 



" " catskillensis Pils. 



So far as I can ascertain this is the first record 

 for this form in Canada. 



Helicodiscus parallelus (Say). 



Mesomphix inornata (Say). 



This seems to be the first Canadian record for 

 this species west of Ottawa. In the United States 

 it ranges from New York southwest through Ohio, 

 into southern Indiana. The supposed records 

 from Michigan are either unauthenticated or 

 fraudulent. 



Zonitoides minuscula (Binn). 

 " arborea (Say). 



Vitrea hammomis (Strom.). 

 " binneyana (Mse.). 

 " lamellidens Pils. 



This rare (in the north) species has hitherto 

 been recorded in Canada only from Ottawa 

 (Walker, Ottatva Naturalist, XIV, 1900, p. 90). 

 Mr. Andrews' discovery extends its range very 

 considerably to the west. 



Vitrea ferrea (Mse.). 

 " indentata (Say.). 



Euconulus fulvus (Dr .) . 



Circinaria concava (Say). 



Vallonia excentrica Sterki. 



Gastrocopta armifera (Say.). 



" tappaniana (C.B. Ads.). 



" contrada (Say.). 



Succinea ovalis Say. 



Cochlicopa lubrica (Mull.). 



Carychium exile H. C. Lea. 



Lymnsea humilis modicella Say. 

 " sp..? 



A single, very small specimen, probably im- 

 mature, with a broadly reflected columella that I 

 cannot place. 



Planorbis parvus Say. 



Physa sayii warreniana Lea. 



I think that this is the first record for this form 

 in Canada. 



Goniobasis livescens (Mke.). 



Pomatiopsis lapidaria (Say.). 



Amnicola sp.? 



A single specimen of a small species that I have 

 been unable to identify satisfactorily. i 



Sphserium striatinum (Lam.). 



Mr. Andrews reports that he saw no signs of 

 there being any Unionidse in the river at Goderich. 



Mr. Justice Latchford states in reference to Dr 

 Walker's paper that he has not had a favourable 

 opportunity to collect shells on his official visits to 

 Goderich, but that once while walking there near 

 the mouths of the Maitland he picked up a living 

 anodonta which he thought to be the variety of 



