42 TEST ACE A ATLANTICA. 



normalls'' of this catalogue) than with those from either 

 Lauzarote or Palma. 



Bulimus pruninus. 



Bulimus pruninus, Gould, Proc. Bost. Soc. Nat. Hist, 190 

 (1846) 

 „ „ Id., Exped. Shells, t. 6. f. 83 (1851) 



„ cyaneus, Alb., Mai. Bldtt. 31 (1852) 

 „ „ Pf&iff; Mon. Hel. iii. 354 (1853) 



„ „ Mouss., Viert. der Nat. Zurich, 166(1858) 



„ tremulans, Id., Ibid. 167 (1858) 

 „ pruninus, Pfeiff., Mon. Hel. i v. 418 (1859) 

 „ „ Morel., Hist. Nat. des Agor. 179. t. 4. 



f. 1 (1860) 

 „ „ Drouet, Fawn. Agor. 159 (1861) 



Habitat Sta. Maria, S. Miguel, et Terceira; vulgaris, ac 

 valde inconstans. 



This is the largest of the Azorean Bulimi, measuring from 

 about 14 to 18 millimetres in length ; and it is, apparently, the 

 most variable shell in the archipelago, — the number of phases, 

 both in colour and sculpture, through which it passes being 

 well-nigh endless. Ten of the more conspicuous of them are 

 alluded to by Morelet, to whose account of the species I must 

 consequently refer. It is in the three eastern islands — Sta. 

 JNIaria, S. Miguel, and Terceira — that the B. 'pruninus is found, 

 and it seems to be as common there as it is unstable, — occurring 

 principally beneath stones, amongst dead leaves, and at the 

 bases of the walls. 



The B. pruninus is a more or less solid shell, and opake, 

 generally roughly striated but sometimes with the strigs obsolete, 

 with the aperture rather angulose at the base, and with the 

 peristome (the upper and lower portions of which are connected 

 by an intervening callus) thickened and (especially towards the 

 columella) expanded. In colour, it is often (except at the 

 apex) blueish or plumbeous, — passing-off however into a yel- 

 lowish- or corneous-brown, as well as into a rosy-white, and even 

 white ; but the blueish or cyaneous tint is often indistinctly 

 traceable in examples in which at first sight it would seem to 

 have totally disappeared. 



Genus 10. STENOGYRA, Shuttl. 

 Stenogyra decoUata. 



Helix decollata, Lin7i., Syst. Nat. (edit. 10), 773 (1758) 

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

 (1831; 



