354 NESOPUP-^ OF THE MASCARENE ISLANDS. 



cosa H. Ad., from Mauritius; there are, however, two pari- 

 etal teetli and within the outer lip a distinct, well-developed 

 tooth, with occasionally another small, indistinct one close to 

 it; the columella is slightly more dilated and subangulated 

 (Nevill). 



Bourbon: near Salazie, in company with V. pupula Dh. 

 (G. Nevill). 



Vertigo (Pagodella) incerta G. NEVILL, Journ. Asiatic Soc. 

 Bengal, vol. 39, pt. 2, 1870, p. 413. 



"This most perplexing of shells can only be distinguished 

 from Pagodellii ventricosa H. Ad. (Proc. Zool. Soc., 1867, p. 

 303) by the different dentition of the aperture; of the latter 

 I found about 40 specimens, to all appearance full grown and 

 in first-rate condition, some of them, to my mind, very old 

 specimens; in none of them were there any signs of any 

 teetli whatever within the outer margin of the aperture ! Of 

 the Bourbon species, I only found 5 specimens, one evidently 

 young, the other 4 full grown and all showing the peculiar 

 characteristics pointed out in my description. Still the re- 

 semblance is so striking that I think no naturalist would 

 hesitate to avow that they must at no very remote period 

 have had a common origin ; there is, indeed, just the chance 

 that at Mauritius a similar variety may exist, but, from the 

 number of specimens I found there, I doubt it exceedingly. 

 I have, however, written to Mr. Dupont at Mauritius to ask 

 him to kindly examine all he can possibly procure of this 

 species, and to see if he can find any trace of the apertural 

 teeth, which give such a different appearance to my V. in- 

 certa" (Nevill}. 



It is curious that, anyone could write so much about a shell 

 and tell so little. 



52. NESOPUPA VENTRICOSA (H. Adams). PI. 33, fig. 6. 



Shell deeply rimate, ovate, rather thin, obliquely striat- 

 ulate, pale brown ; spire convexly conic, the suture impressed. 

 Whorls 5, somewhat convex, the last ventricose, rounded at 

 base. Aperture semioval, provided with a compressed, en- 

 tering parietal fold and a tooth at the insertion of the right 



