22 BRITISH MOLLUSKS. 



are its livid glaucous colour and its gelatinous substance, often so 

 translucent that the internal organization may be traced. Typical 

 specimens, such as the one represented in our figure, are moreover 

 characterized in all stages of growth by two conspicuous loops of 

 black bands, one on the shield, the other on the back reaching to 

 the extremity of the tail. In examples of the species in a young 

 state, with drawings of which, made as long back as 1828, Mr. Berke- 

 ley has obligingly favoured me, the black loop-like bands are still 

 a prominent feature. The shield is rounded in front, and widening 

 over the pulmonary sac, terminates posteriorly in an angular slope. 



The habits of L. marginatus are variously described by different 

 observers. It is most frequent on beech, ash, and walnut trees. 

 Mr. Thompson says : " After rain, I have seen them in numbers, 

 gliding down the smooth bark of the beech from feeding on the 

 higher foliage, their bodies appearing between the light like pellucid 

 jelly." Forbes and Hanley mention having collected the species 

 near Connor Cliffs in the west of Ireland, in a rocky locality entirely 

 devoid of trees ; and Mr. Clarke notices having met with it among 

 the ruins of a chapel in Connemara, crawling in considerable num- 

 bers on the walls and tombstones. 



The shell is variously developed : sometimes it is of a thin silveiy 

 white substance partially membranaceous, sometimes rather thick, 

 slightly convex above, concave below. 



5. Limax brunneus. Brown Limax. 



Animal ; body tapering, rounded on the back, slightly keeled to- 

 wards the tail, dark dingy brown throughout ; shield oblong- 

 oval, large, concentrically ridged and striated. 



Shell ; ? 



Limax brunneus, Draparnaud (1801), Tail. Moll. p. 104. 



Hob. North-east of England (in damp woods) ; Johnston, Alder. Pas-de- 

 Calais, France (common on the banks of rivers and brooks, and under 

 moss and stones) ; Bouchard- Chan tereaux. 



