COLLIER: NOTES ON THE SECTION TACHEA OP HELIX. II9 



banks and old walls in abundance. They are sometimes found 

 climbing trees and hedgerows, and at Lisdoonvarna Spa, in co. Clare, 

 I found abundance of our H. tiemoralis quite high up in a thorn 

 hedge. At Corbeyrier-sur-Aigle, in the Rhone Valley, at an altitude 

 of 2,500 feet, I found the same species in an orchard, a long way up 

 the apple-trees, and I had to get a long pole with which to push 

 them off. 



They colonize freely, and H. nemoralis is said to have increased 

 rapidly since it was introduced into North America. 



Most writers assign the following nine species to Tachea : — 

 Helix atr-olabiata Krynicki. 

 Helix vindobonensis C. Pfeiffer. 

 Helix nemoralis Linne. 

 Helix hortensis Miiller. 

 Helix sylvatica Draparnaud. 

 Helix coquaudi Morelet. 

 Helix splendida Draparnaud. 

 Helix aiinophila Bourguignat. 

 Helix vlcaria Westerlund. 



Besides these, H. gibbonda Desh. and H. filosa Desh., both of 

 unknown habitat, may be synonymous with one of the above species; 

 while H. litturea .Pfr., also with habitat unknown, is perhaps a form 

 of H. sylvatica. 



H. (Tachea) atrolabiata Krynicki. — 



This species is the largest of the section, and its distribution is in 

 the Caucasus, Georgia and Imeretia, and in Persia, along the southern 

 shore of the Caspian Sea. 



This species varies considerably : the var. lenkoranea Mouss., 

 looked at from above, might almost be taken for a form of our 

 common H. aspersa, but it has the mouth of a true Tachea, whereas 

 the var. neinoraloides Mart, looks like a glorified H. ne/noralis. 



H. (Tachea) vindobonensis C. Pfr. = austriaca Muhl— 



This species is very like our H. nemoralis, but is more globose and 

 strongly striate, with the usual five bands ; it is also found without 

 bands (var. expallescens Zglr.). 



It is found in Central and Eastern Europe as far as the Caucasus. 

 It seems to live in the districts where H. nemoralis has so far not 

 yet penetrated, although on the borderland the two species are found 

 together, but apparently it is being driven further east by the more 

 dominant H. nemoralis. 



