PUPA. 251 



the beach by the reflux of the tide. I have often found 

 it under such circumstances mixed with recent sea-shells 

 on a flat sandy coast. The Rev. Revett Sheppard says 

 that i, occurs "in profusion in Essex^ near Wrabness 

 Point, on the upper part of the marsh — a situation which 

 at high tides is covered with water.^^ The foreign range 

 of this species is very extensive. Middendorft*, as well 

 as Gerstfeldt, has recorded it as Siberian ; Von Martens 

 has noticed it as inhabiting Iceland and Lapland ; it is 

 common in Scandinavia ; and southwards it has found its 

 way to Central Europe, Spain, Corsica, and Sicily. 



This is a hardy and fearless little animal, and crawls 

 rapidly for its size, compared with the movements of 

 P. ringens. According to Moquin-Tandon this species 

 is ovo viviparous, as well as P. umbilicata, and the young 

 are sometimes attached to the shell of the mother and 

 carried about by her. The work of reproduction takes 

 place in the months of July and August. The number 

 of eggs varies from 3 to 7. In some specimens the spire 

 is much longer or shorter, and the shell is consequently 

 narrower or broader than usual. The epiphragm is like 

 that of the last species, but is seldom complete. 



This difiers from P. umbilicata in the shell being more 

 cylindrical and mostly of a smaller size, as well as in the 

 mouth being semioval instead of triangular, but more 

 especially in having a strong back rib instead of a re- 

 flected lip. The present species seems to connect Pupa 

 with Vertigo. 



In consequence of the hopelessly inextricable confusion 

 which has so long existed as to the identity of Linnets 

 Helix muscorum with this or the last species, or the 

 Pupa minutissima of Hartmann (and which confusion 

 seems to be increased by every new writer on the sub- 

 ject), there scarcely seems to be any alternative but to 



