CAPE-VERDE GROUP. 509 



genus akin to the Pupa umbilicata, Drap., and (more particu- 

 larly) to its smaller state, which was described by Lowe under 

 the name of P. anconostoma. Indeed, judging from the shell 

 alone (and I am not aware that the animal has ever yet been 

 noticed), I cannot see any very great reason why it should be 

 separated from the Gastrodon-division of the Pupce ; though 

 since it is treated as a Bulimus both by Benson and Dohrn, I 

 will not attempt to refer it to any other group. I am surprised 

 however that neither of those naturalists should have noticed the 

 fact that the obscure parietal tooth which is sometimes traceable 

 near the upper angle of its aperture is as often absent as pre- 

 sent^ thus confirming the analogous inconstancy of the same 

 character in the Pupa anconostoma and Dohrni, as distin- 

 guished from their central prototype the common P. umbilicata 

 of Draparnaud. Amongst other features of the B. gemmula, its 

 broadly expanded but acute peristome, the convexity of its few 

 volutions (which are only five in number), and the singular habit 

 which it possesses of coating itself over with a hardened envelope 

 of dirt (which perhaps is more suggestive of Bulimus than it is 

 of Pupa) should be particularly noticed. The B. gemmula 

 varies in length from about 1 J to 2 lines. 



So far as has been observed hitherto, there is no shell which 

 is so universally spread over the Cape Verde archipelago as this 

 diminutive and insignificant Bulimus, it having been detected 

 in all the islands except the three eastern ones, which however 

 may be said to be as yet, practically, unexplored. It was first 

 found by Mr. E. L. Layard, now many years ago, in S. Vicente, 

 while halting there on his passage to the Cape of (rood Hope ; 

 and Dohrn has subsequently met with it not only in that island 

 but likewise in S. Antao, S. Nicolao, and S. lago. By myself 

 it was taken in S. Vicente, Fogo, and Brava. 



Genus 6. STENOGYRA, Shuttlw. 



Stenogyra decollata. 



Helix decollata, Linn., Syst. Nat. (edit. 10). 773 (1758) 

 Bulimus decollatus, Lowe, Cambr. Phil. S. Trans, iv. 62 



(1831) 



Id., Proc. Zool. Soc. Lond. 199 (1854) 



Alb., Mai. Mad. 54. t. 14. f. 16, 417 



(1854) 



Morel., Hist. Nat. des Acor. 196 (1864) 



Stenogyra decollata, Mouss.,Faun. Mai. des Can. 120 (1872) 



Bulimus decollatus, Morel., Journ. de Conch, xiii. 238 (1873) 



Habitat S. Nicolao, et Boavista ; a Dom. de Cessac nuper 



detecta. 



