TAYLOR : RIOLOGV OF THE NFOLLUSCA. 267 



ally, the Roman snail Helix pomalia, which occupies Central and 

 Eastern Europe. Its natural range at the present day is the West of 

 Europe and the circum-Mediterranean region, as it is quite unknown 

 in Northern, North-Central, and Eastern Europe, except in a few 

 isolated gardens, where it has been artificially introduced. 



Though naturally restricted to the areas described, this species, 

 being one of the most highly organized and dominant Helices in the 

 world, is a great colonizer, and has by human and other agencies 

 been accidentally or purposely transported to almost every part of the 

 more temperate regions of the world ; its superior adaptability and 

 organization enabling it to maintain its foothold in new regions, and, 

 like the white man, gradually to dispossess the more feeble species 

 which had previously lived there. 



Being relatively so highly endowed and dominant, we may look 

 for some display of intelligence, and careful observation has demon- 

 strated that our H. aspersa and other species share with man the 

 love of home, for it will traverse broad dusty roads and climb rough 

 walls to reach some favourite food, and when satisfied does not secrete 

 itself near by, in any convenient crevice, but laboriously returns by 

 the often toilsome and disagreeable path to reach its home before dawn. 



It has also been observed in the course of its nocturnal wanderings 

 to describe by its path the same double-loop or figure of 8 as the 

 common limpet does in its intertidal forages, and which when first 

 discovered created such great interest. 



In connection with these more or less temporary retreats, I may 

 allude to the more permanent ones which have been resorted to for 

 centuries, and have by the constant attrition of the foot become 

 quite deep and spacious. These retreats or galleries, which are 

 mainly found in cliffs of carboniferous limestone with an east or 

 north-east aspect, invariably take an upward direction, perpendicular 

 to the bedding of the strata, and were formerly surmised to be the 

 work of the Pholads or other marine-boring bivalves, but the char- 

 acteristic ascending tendency of these helicidian cavities clearly dis- 

 tinguishes them from those of the marine-boring bivalves, which 

 usually descend, with the entrance opening above. 



The Uses to which this species was formerly put or even used for 

 at the present day are far from being insignificant. In comparatively 

 modern times this species with others was included in the Materia 

 Medica, and was held in great esteem for a variety of ailments, while 

 as a remedy for consumption and colds they are still in good repute 

 in some parts of our own country, and they make an effective lini- 

 ment for stains and bruises when melted down and mixed with 

 ammonia, 



