138 PNEUMONOBRANCHIATA. 



Arianta arbustorum. Leach, Moll p. 86. 



Cochlea unifasciata. Da Costa, p. 75. t. 17. f. 6. 



Inhab. moist woods and river sides, in wet shady 

 places among willows. 



Animal granular, greenish black ; hinder part of 

 the foot and beneath, grey; tentacles shortish. 

 (Sturm, t. 23.; Rossm. t. 5. f. 7, 8.) 



Shell about three quarters of an inch high, and as 

 much in diameter, but variable in size and proportion, 

 striate, mostly brown marbled with small yellowish 

 spots, or greenish-yellow with whitish spots, with a 

 single blackish band, which winds round the middle 

 of the lowest volution and continues round the base 

 of the rest, not penetrating the aperture : this band is 

 often faint, rarely wanting; aperture semielliptic, 

 longer than wide, more produced at the pillar side, 

 with the margin slightly reflected and white, with a 

 white internal rib. 



The young shells have a thin lip, with a slight 

 white internal rib. 



It varies — 1. In colour, from dark chestnut to pale 

 yellowish white, with only a few whiter specks. 



2. In the thickness of the shell, the thinner specimens 

 being generally destitute of the band. 



3. In the presence or absence of the band. 



4. In the size, according to the locality. The 

 small mountain variety has been called a species by 

 the Swiss shell dealers. 



It is sometimes distorted — 1. by the whorls being 

 reversed; 2. the spire more or less elevated or 

 depressed; 3. very rarely the whorls are elevated and 

 separated from one another. (See Term. Hist. t. 29. 

 f. 1, 2, 3.) 



