CLAUSILIA. 279 



well as with a few indistinct spiral striae, the intersection of 

 which gives the surface a slightly granular appearance : peri- 

 pheri/ angiilar or ridged : ejjidermis rather thin : whorls 12-13, 

 compressed, regularly increasing in size, the last being equal 

 in bulk to about one-third of the shell, but somewhat nar- 

 rower than the two or three j)receding whorls ; the first whorl 

 nij^ple- shaped and quite smooth : S2nre tapering to an obtuse 

 point : suture rather oblique, slight but distinct : mouth almost 

 funnel-shaped, compressed on the outer side, and having an 

 effuse base, like the lip of a water-jug; teeth or folds as 

 follows : — two on the pillar, the upper one of which is promi- 

 nent and oblique and forms one of the sides of a channel at 

 the outer angle, and the lower one is smaller and more sunk 

 or deeply seated, being also oblique and sometimes bifurcate, 

 and between these are occasionally from one to three smaller 

 folds or ribs ; one strong but deep-seated and not very distinct 

 crescent-shaped fold (or hmeJJa) on the pillar hp; one still more 

 sunken and very slight spiral fold near the last ; and occasion- 

 ally one or two teeth (like those in Pupa) within the outer lip : 

 the outer Up is thick, white, and reflected : based crest sharp and 

 angular, transversely ridged: umbilicus much contracted by 

 the intortion of the mouth : clausiUum oval- oblong, regularly 

 curved, sHghtly dilated above. L.0'5. B.0-1. 



Yar. 1. albida. Shell greenish-white, with a few white 

 transverse lines. 



Yar. 2. Eueretti, Miller. Shell smaller. 



Yar. 3. gracilior. Shell longer and more slender. 



Yar. 4. tmnidula. Shell smaller, shorter, and more ven- 

 tricose. 



Yar. 5. dnbia. Shell larger and more ventricose. Cdubia, 

 Drap. Hist. Moll. p. 70, pi. iv. f. 10. 



Yar. 6. dextrorsa. Shell resembling a Pupa in shape : spire 

 dextral. 



Habitat : On old walls and rocks, as well as under 

 stones and on the trunks of trees, throughout these isles, 

 from Zetland to Guernsey. Var. 1. Dinton Hall, Bucks 

 (Goodall). Var. 2. Bristol (Miller) ; Whalsey Skerries, 

 Zetland ; Giant's Causeway and Co. Tyrone (J. G. J.). 

 Var. 3. Battersea marshes (J. G. J.). This last variety 

 appears to be the Crugulosa of Ziegler. Y"ar. 4. Brockley 



