LAND SNAILS 



Of Uncertain Presence in Illinois 



From certain places in Illinois have been recorded several 

 species of land mollusks not found in collections made by the 

 molluscan survey of 1931-1932 or in any other collections 

 studied by the author of this fieldbook. Since the student may 

 encounter these names in papers on Illinois mollusks, and par- 

 ticularly since they appear in A Catalogue of the Mollusca of 

 Illinois, published in 1906, it has been deemed important that 

 they be noted and commented upon. Page references below are 

 to the Catalogue. 



Bifidaria pentodon ftoridana Dall. Page 112. 



Known in present literature as Gastrocopta pentodon flori- 

 dana (Dall), this form is found in Florida. The shell upon 

 which the Illinois record is based is believed to be only a slight 

 variation of the typical Gastrocopta pentodon. 



Pupilla muscorum (Linnaeus). Page 112. 



This species is listed from Mercer County by Marsh. It has 

 not been found in any collection examined by the author of 

 this fieldbook, and its presence in Illinois is doubtful. It is rare 

 in Michigan and is not recorded from Indiana. 



J ertigo gouldii Binney. Page 112. 



This small pupoid is recorded by Hinkley from Rockford, 

 Winnebago County, and by Marsh from Will County. Vertigo 

 gouldii is a northern species, common in Michigan and Minne- 

 sota, but its presence in Illinois is to be strongly doubted. It 

 has not been found in Indiana. 



Succinea nuttalliana Lea. Page 114. 



Recorded from Rockford, Winnebago County, by Hinkley 

 and from Fulton County by Wolf, this is a western species 

 inhabiting Oregon and California; hence, its presence in Illinois 

 is to be questioned. The record is without doubt founded on 

 specimens of Succinea retusa, which greatly resemble nuttalliana. 



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