LIMNJLA. 117 



Moquin-Tandon states that lie had observed it in the 

 Pyrenees at a height of 1200 metres (nearly 4000 feet) ; 

 and instances of its occurring at a tolerable elevation in 

 this country might doubtless be also given, as I have 

 found it living at the sides of all our mountain tarns, 

 but no other animal in company with it. It deposits its 

 spawn on the mud, which is its usual habitat, and not, 

 like its congeners, on the stalks and underneath the leaves 

 of water-plants. 



The form of its shell somewhat resembles that of L. 

 peregra, var. maritima ; but its minute size and turricu- 

 lated spire will serve to distinguish the present from 

 any other species. This is the Limneus minutus of Dra- 

 parnaud and Helix fossaria of Montagu. The name it 

 now bears seems to have been derived, not from the 

 truncature or decollation of the spire, but from the 

 truncate or turreted form of the whorls. 



8. L. gla'bra^, Miiller. 



Buccinum glahrum, Miill. Yerm. Hist. pt. ii. p. 135. Limnaus glaher, 

 F. & H. iv. p. 178, pi. cxxiv. f. 1. 



Body dusky-grey with a tinge of slate-colour, covered with 

 minute, but distinct, black specks : tentacles rather long : eyes 

 placed on prominent tubercles : foot truncate in front, from 

 which it spreads a little towards the rear, ending in a thick 

 and narrow tail. 



Shell cyHndrical, rather thin and glossy, greyish-horn- 

 colour or brownish, sculptured as in the three preceding species : 

 epidermis very thin : whorls 7-8, rounded but not very convex, 

 the last occupying not much more than half the shell : spire 

 produced and ending in a somewhat blunt point : suture slight, 

 but distinct, margined as in the two foregoing species : mouth 

 pear-shaped, contracted above at an acute angle, and furnished 

 inside with a thick broad white rib, which is placed at a httle 

 distance from the opening : outer lij) thin, scarcely reflected : 



* Smooth. 



