SPECIES OF UNCERTAIN PRESENCE 



149 



is dull, not shining. The aperture is rounded in mitclielliana, 

 while it is transversely narrowed in penusylvanica. 



Omphalina inornata (Say). Page 119. 



Now known as Mesomphix inornatus. this species has been 

 recorded from La Salle County by Calkins. No specimens of 

 this characteristic species have been seen from Illinois by the 

 author of this fieldbook. It occurs in southeastern Indiana. 



Retinella cryptomphala (Clapp). 



Two records of this species have been published as from 

 Illinois. Clapp, in Nautilus (Volume 29, page 26, 1915) lists 

 Albion. Edwards County, in the distribution. Hinkley {Nauti- 

 lus, Volume 33, page 15, 1919) lists it from Dubois, Washington 

 County. Specimens from these two places are in the University 

 of Illinois collection, which includes the Edwards County speci- 

 mens upon which Clapp's record is based. These specimens have 

 a closed umbilicus with a callus, as described by Clapp. There 

 are 150 lots of Retinella indent at a in the Illinois collection, 

 embracing approximately a thousand specimens; among these 

 a half dozen individuals have the com- 

 pletely closed umbilicus. In the writer's 

 opinion, the specimens referred by 

 Clapp and Hinkley to cryptomphala 

 should be referred to indentata as 

 pathologic specimens, unless the cryp- 

 tomphala is simply an indentata with 

 a closed umbilicus. Specimens of the 

 supposed cryptomphala submitted to 

 Dr. Henry A. Pilsbry were referred 

 by him to indentata. No authentic 

 specimens of Retinella cryptomphala 

 have been seen from Illinois. It is 

 common in Tennessee. A shell of the 

 snail Retinella cryptomphala (Clapp), 

 selected from Tennessee specimens, is here figured for reference 

 by Illinois collectors. 



Vitrina limpida Gould. Page 119. 



Recorded from La Salle County by Marsh, this is a northern 

 species, living in Michigan and Minnesota. The reference in 



