57 



LIMNEA longiscata. 

 TAB. CCCXLIII. 



Spec. Char. Elongated, smooth ; aperture o- 

 vate, elongated, two-fifths the length of the 

 shell ; plait upon the columella obscure. 



Syn. Limneus longiscatus? Srongniart Me- 

 moir e sur des Terrains formes sous Veau douce, 

 p. 16. t. \. f. 9. Amiales du 3Ius. torn. 15. 

 t. 22, /. 9. 



A SHELL rendered conspicuous by the length of its 

 spire, and the broad obtuse edge of the columella which 

 hardly rises in the form of a plait. The volutions are 

 not inflated in general, but in many specimens the upper 

 ones are a little so at their lower parts, so as to project 

 over the following turns ; the aperture is nearly twice as 

 long as wide, its inner lip is a little relieved ; the sur- 

 face is regular and shining, with the lines of growth 

 finely marked. 



This seems to have a wider and shorter aperture than 

 the figure given by Brongniart of his Limneus longiscatus, 

 but as it is liable to some variation 1 have ventured to 

 refer it to that species, although I have not seen authen- 

 tic specimens for comparison ; should a difference really 

 exist, it may distinguish the species of the upper from 

 the lower fresh water formations : Brongniart found his 

 shell only in the lower ; the one figured is from the up- 

 per ; it was collected by Mr. G. B. Sowerby upon Headou 

 Hill last year. 



