56 



BltlTISH MOLLUSKS. 



types is probably due to transportation. H. aspersa has become 

 naturalized by transportation, both in the United States and in 

 Brazil. Varieties of H. nemoralis are also located in the States. 

 The only British Helix which appears to be indigenous to the 

 United States is that which has the widest distribution in the 

 Eastern Hemisphere, the little H. pulchella, — a very interesting 

 feature in the phenomena of distribution. There are, however, two 

 other species, H. fulva and rupestris, which have very near re- 

 presentatives, in the United States, in H. chersina and saxicola. 



Distribution of British Helices. 









Other, Parts of 



Species. 



Britain. 



Europe. 



the World. 



aspersa. 



Throughout. 



Central and South. 



N. Africa, Azores, 

 United States, 

 Brazil. 



arbustorum. 



Throughout. 



Throughout. 





nemoralis. 



Throughout. 



Throughout. 



United States. 



hispida. 



Throughout. 



Central and South. 



Siberia. 



fusca. 



Throughout. 



West France. 





fulva. 



Throughout. 



Throughout. 



Siberia, Azores. 



aculeata. 



Throughout. 



Throughout. 



Azores. 



pulchella. 



Throughout. 



Throughout. 



Siberia, Thibet, Ma- 

 deira, Azores, 

 United States. 



rotundata. 



Throughout. 



Throughout. 



Azores. 



rupestris. 



Throughout. 



Central and South. 





pygmcea. 



Throughout. 



Throughout. 



Siberia, Azores. 



virgata. 



Nearly throughout. 



Central and South. 



N. Africa. 



fasciolata. 



Nearly throughout. 



Central and South. 



N. Africa. 



ericetorum. 



Nearly throughout. 



Central and South. 





lapicida. 



Ceutral and South. 



North and Central. 





rufescens. 



Central and South. 



Central and South. 



N. Africa, Madeira. 



Cantiana. 



Chiefly South-east. 



South-west. 





Carthusiana. 



Chiefly South-east. 



Central and South. 





Pisana. 



South and West. 



South. 



Canaries, Azores, 

 N. Africa. 



sericea. 



Chiefly South-west. 



Throughout. 



Siberia, Caucasus. 



revelata. 



South and West-south. West France. 





pomatia. 



South and Central. 



Central. 





ohvoluta. 



South (doubtful). 



Central. 





lamellata. 



North. 



North. 





