EUROPEAN SPECIES OF VERTIGO. 159 



Comparison of the whole series now at hand shows that this 

 is merely a slight variant from another island, doubtfully 

 separable from the original dedecora. 



III. PAUEARCTIC SPECIES, EUROPE, ASIA AND NORTHERN 



AFRICA. 



The European Vertigos have never been monographically 

 studied. Westerlund's several works are synoptical compila- 

 tions not really aiming to be critical monographs, I presume ; 

 and the extensive and valuable papers of Gredler and 

 Boettger, as well as the several faunal manuals, such as those 

 of Clessin and others, cover only part of the ground. Wester- 

 lund has carefully described many new forms from Sweden, 

 where the genus appears to have an extraordinary develop- 

 ment; but they have not been figured, and most of them are 

 to be found in very few collections, or in but one, many 

 being practically unknown outside of Sweden. 



Most of the species of Central Europe have been figured by 

 Kobelt, Geyer and others, in lithographs, and by Steenberg 

 in admirable pen drawings, among the best figures of Vertigo 

 ever published. Having no special knowledge of European 

 species, and possessing few of them, the author has compiled 

 most of the following account from the original publications. 



NORTH AFRICAN SPECIES are all supposed to be distinct from 

 those of Europe. They are still known only by Bourguignat 's 

 work of over 50 years ago. 



V. discheilia Bgt, no. 49. V. briobia Bgt,, no. 59. 



V. maresi Bgt., no. 50. V. microlena Bgt., no. 60. 



V. aprica Bgt., no. 57. V. latasteana Bgt. & Let., no. 45. 

 V. codia Bgt., no. 58. 



Westerlund has constructed a partial key to Palaearctic 

 species, which is recast below with some small alterations. 



1. Shell dextral. 2. 

 Shell sinistral. 9. 



2. Aperture toothless ; neck scarcely impressed in front, 

 without an encircling crest; no internal palatal callus: 



