210 EUROPEAN SPECIES OF VERTIGO. 



of Joukoping, southward, where it occurs with V. pin-eticola, 

 ovoidea, arctica and others of the genus, upon twigs and fallen 

 leaves. 



80. VERTIGO CLEVEI Westerlund. 



Shell [sinistral] obesely ovate; whorls 5y 2 , convex, the 

 penult inflated below, the last scarcely higher, much narrower, 

 impressed at the aperture. Aperture truncate-ovate, the outer 

 margin arcuate above, straight in the middle, oblique; basal 

 margin rounded. Teeth only 2, one each on the parietal 

 wall and the columella. Length 1%, diam. 1 mm. (West.). 



Sweden: Sala, in a place called Grona gaugen (Prof. P. T. 

 Cleve). 



Pupa clevei WEST., Fauna Pal. Reg. Binnen-couch. iii, 1887, 

 p. 142. 



Subgenus VERTILLA Moquin-Tandon. 



Vertilla M.-T., Hist. Nat. Moll. terr. et fluv. France ii, 

 1855, p. 408, for V. plicata and V. pnsilla. 



Angular and parietal lamellae well developed, the angular 

 not connected with the peristome, parietal long; columellar 

 lamella subvertical, spirally entering above. Upper palatal 

 fold very long, its inner end curving down ; the lower palatal 

 short or wanting. Type V. angustior Jeffr. (V. plicata Moq.). 



This group differs from Augustula by having the columellar 

 lamella of entirely different form, and the upper palatal fold 

 penetrating deeply, its inner end decurved and somewhat 

 hook-like (as in pi. 5, fig. 17). In August ula and most species 

 of Vertigo the upper palatal fold is shorter than the lower. 

 While Anguxtula and Vertilla show a certain parallelism or 

 convergence, there appears to be 110 direct or close relationship. 

 Vertigo angidifera Boettger, a dextral species of the German 

 Miocene, is said to be closely related to V. angustior, and prob- 

 ably is ancestral to the recent species. 



Vertilla was proposed for sinistral species of Vertigo, in- 

 cluding the type of the genus ; and the name has been exten- 

 sively used by European authors in this sense. The sinistral 

 forms have obviously been derived from several dextral stocks 



