148 SPECIES OF UNCERTAIN PRESENCE 



Succinea higginsi Bland. Page 114. 



Described from Put in Bay on Lake Erie, this species was 

 recorded from Rock Island County by Marsh. It is possible 

 that a form of Succinea ovalis might have been mistaken for 

 this species. 



Succinea aurea Lea. Page 114. 



This species, recorded from Effingham County by Marsh, is 

 known from Ohio and from Clark County, Indiana. No speci- 

 mens have been seen from Illinois by the author of this fieldbook. 



Succinea grosvenorii Lea. Page 1 14. 



This species was recorded by Nason and Wolf from Canton, 

 Fulton County. The specimens thought by these men to be 

 grosvenorii are now known to be minor variations of Succinea 

 avara. 



Polygyra sayii (Binney), same as Polygyra sayana Pilsbry. Page 

 115. 

 Recorded from northern Illinois by Calkins and from Edgar 

 County by Marsh, this very distinct species has not been seen in 

 any Illinois collections examined by the author of the present 

 work. It is about three-fourths inch in diameter, has a wide 

 and deep umbilicus and a heavy denticle on the parietal wall. 

 The records might have been founded on small specimens of 

 the unicolored form of Polygyra profunda. Polygyra sayana 

 has not been recorded from Indiana and in Michigan is known 

 only from the northern part of the state. It is common in the 

 eastern part of the United States. 



Polygyra mitchelliana (Lea). Page 117. 



This Polygyra has been recorded from three counties: from 

 La Salle by Baker and Calkins, from Mercer by Marsh and 

 from Fulton by Strode. No specimens of the true mitchelliana 

 have been seen in any of the material examined by the author 

 of this fieldbook. Several lots labeled under this name proved 

 to be small specimens of Polygyra pennsylvanica. Polygyra 

 mitchelliana may inhabit some part of Illinois not yet examined, 

 for it occurs in Indiana and Michigan. It is a smaller species 

 than pennsylvanica, which has a heavier shell, a much thicker 

 reflected peristome, a sculpture that is coarse and a surface that 



