350 NESOPUP^E OP THE MASCABENE ISLANDS. 



the angular and parietal lamellae are eoncrescent into one 

 sinuous lamella. 



The Vertigininae have been very poorly described, and only 

 two of the nine species are at hand for examination. One 

 subgenus, Nesopupa, is common to these islands and Poly- 

 nesia; another, Insulipupa, is common to the East Indies, 

 India, the Mascarene Islands and Africa. Several other 

 species, in the absence of specimens or adequate figures, can- 

 not safely be classified. The species borbonica and desmazu- 

 resi resemble the East Indian group Costigo in teeth, and 

 have provisionally been placed there. 



Key to Species. 



a 1 . Aperture having both angular and parietal lamellae. 



ft 1 . Angular lamella strongly developed, rather long 

 and high ; columellar lamella entering deeply, dilated 

 and curving downward at the inner end (Nesopupa) . 

 c 1 . Length 2.5 mm., about 8 teeth. 



N. gonioplax, no. 47, 

 c 2 . Length 1.5 mm., at least 5 teeth. 



N. micro,, no. 48, 



b 2 . Angular lamella small and much lower than the 

 parietal; columellar lamella subhorizontal, not 

 turned down within (Insulipupa) . 



c 1 . Species of the Comoros, having 5 or 6 teeth. 

 d 1 . 2x1 mm. N. minutatis, no. 49. 



d 2 . 1.5 x 0.75 mm. N. comorensis, no. 50. 

 c 2 . Bourbon ; 4 to 5 teeth, 1 or 2 palatals. 



N. incerta, no. 51* 



c 3 . Mauritius; angular, parietal and columellar 

 lamellae only, no palatals. N. ventricosa, no. 52. 

 a 2 . Parietal lamella present, but no angular; 1 columellar, 2 

 palatals. 



ft 1 . 2.5 x 1.33 mm. ; Bourbon. Costigo borbonica, p. 367. 



b 2 . 2.25 x 1 mm. ; Rodriguez. Costigo desmazuresi, p. 368. 



a 3 . No teeth on the parietal wall; columellar lamella, basal 



and two palatals present ; apex very obtuse ; length 2 mm. 



"Vertigo" praslinensis, no. 53. 



