2IO Natural History Bulletin. 



cinca ovalis) all are strictly terrestrial in their habits. The 

 following species are now found in North America only in 

 mountainous regions, or far to the north of the region now 

 covered by the Loess. 



Pu^a decora. Pupa alticola. 



Pupa musconim. Sticcinca vcn'Ui. 



Patula stn'g'osa coopcri. 



Of the species Pupa muscoruui is circum polar, but while on 

 this continent a boreal species, it ranges in the Old World 

 from Siberia to Sicily.' 



In addition to this species the following are also circum- 

 polar, but extend into, or even south of the Interior region as 

 limited by Binney : 



Zonites radiatnJus Vallonia pidchella, 



Zonitcsfulviis. Fcrussacia suhcylindrica. 



Those which are northerly in distribution, but are also 

 abundant in the latitude of the Loess deposits are the following: 



Zonites limatitlus. Snccinca ovalis. 



Patulns striatclla. Succinea avara. 



Vertigo gouldii. JLimncBu caperata. 



The following additional species range over all of the conti- 

 tinent east of the Rocky Mountains, those marked (*) occur- 

 ing throughout the United States: 



'* Zonites arboreus. '" Vertigo ovata. 



'^Zonites miniiscidns. Succinea obliqua. 



'^Helicodiscus lineatiis. Carychiiini exigiium. 



Patida alternata. Linincea kiunilis. 



Pupa pentodon. Planorbis -parvus. 



Ptipa arniifera. 

 The remaining identified species are restricted approxi- 

 mately to the latitude of the Loess. 



Helicina occulta. Mesodon nudtilincaia. 



Stenotrema leait. Succinea lineata. 



himncca Juunilis parva. 



1 "Binney, Vol. V.," page 198. 



