Mollusks. 4263 



Zonites excavatus. Three specimens of this rare shell were unex- 

 pectedly obtained last year, from an old loose tree-stump, in the wood 

 at Winterset. 



Succinia putris. Occasional, but not by any means so abundant as 

 S. Pfeifferi, which, though small, swarms in the same locality as 

 Zonites lucidus. 



Bulimus obscurus. Not common ; perhaps overlooked from its 

 power of concealment. 



Zua lubrica. Common, at roots of grass, &c. 



Achatina acicula. Several specimens of this shell from the lime- 

 stone at Went Vale, but only two or three inhabited. 



Pupa umbilicata. Common. 

 „ marginata. A few dead, but good specimens, from the moist 

 earth of the same locality as Achatina acicula. 



Vertigo. Some of these neat little shells have been obtained from 

 the magnesian limestone crags at Went Vale, chiefly among the 

 debris that has collected by the side of the rocks and become mixed 

 with the vegetable mould and decayed leaves below. By filling a bo- 

 tanical case with this earth, and examining it at leisure, I have pro- 

 cured at one forage above one hundred and sixty specimens of pusilla 

 (not many alive, but the shells in good condition), some thirty or more 

 of pygmsea, and about fifty of edentula, besides two or three of 

 substriata and cylindrica, with dozens of several commoner shells. 



Vertigo palustris. A few score specimens from the wet grass, on 

 the banks of Hemsworth Dam. 



Clausilia nigricans. Common, in the woods among tree-moss, &c. 



Carychium minimum. Common, at roots of mossy grass. 



Limnaeus auricularius. Not uncommon at Hemsworth and Win- 

 terset. 



„ pereger and its variety lineatus. Common. The vars. 



acutus and lacustris not so common. 



„ palustris. A few specimens from small field-pools. 



„ truncatulus. Abundant in grassy ditches. 



„ glaber. Abundant in one meadow-pool, confined to a 



few square yards. The peculiarity giving rise to var. lineatus, in L. 

 pereger, I have observed in all the species of this genus. 

 „ fluviatilis. Not uncommon. 



Velletia lacustris. Pretty common in one small pond, adhering to 

 grass, &c. 



Physa fontinalis. Abundant in the mill-pond. 



Aplexus hypnorum. Not common. 



