220 TEST ACE A ATLANTIC A. 



with adhering to the broken sticks and small stones near the 

 minute trickling streams, as well as beneath damp moss. Under 

 such circumstances it was first taken by myself, and subsequently 

 by Mr. Lowe, on the 18th of July 1850, at the extreme head of 

 the Ribeira de Joao Delgada ; and it was afterwards found by 

 Mr. Lowe on the north side of the Pico Casado at the head of 

 the Boa Ventura. 



In outline and size the P. concinna is in reality more 

 nearly related to the P. laurinea ; nevertheless it is darker, as 

 well as more densely and coarsely striated, than that species, 

 and its two ventral plaits are more flexuose and oblique, or less 

 vertical (causing the sinus to be even still more closed in), the 

 external one being also more completely unconnected by even a 

 rudimentary callosity with the angle of the lip. 



Pupa laurinea. 



Pupa laurinea, Loiue, Ann. Nat. Hist. ix. (1852) 

 „ „ Pfeiff., Mon. Hel. iii. (1853) 



„ „ Loive, Proc. Zool. Soc. Lond. 209 (1854) 



„ „ Alb., Mai. Mad. 64. t. 15. f. 31, 32 (1854) 



„ „ Paiva, Mon. Moll. Mad. 126 (1867) 



Habitat Maderam sylvaticam ; ad truncos Laurorum, inter 

 muscos, degens. In statu semi/ossi^ij uxta Cani9al reperitur. 



The P. laurinea is in some respects intermediate between 

 the concinna and sjpliincto stoma. Indeed in its rather short, 

 obtuse, cylindric-oval form and general size and proportions it 

 almost coincides with the foi'mer ; nevertheless it is a little 

 wider (relatively), and more obese, than the concinna, as also 

 less distinctly striate, and (on the average) a trifle more shining 

 and brightly coloured, — it being usually of a more or less clear 

 olivaceo-yellowish brown and appreciably (often indeed con- 

 spicuously) banded. Moreover its ' sinus ' is rather less de- 

 cidedly closed-in behind (the result principally of the first 

 ventral plait being more vertical in its direction, or less oblique), 

 whilst ajiteriorly it is nearly always bounded by a more or less 

 developed (though occasionally thin) corneous sphincter, be- 

 tween the ventral plait and the angle of the lip. Indeed this 

 sphincter not unfrequently assumes the shape of a nearly se- 

 parated tuberculiform process, or transverse plait-like tooth ; 

 and in a very few (exceptional) instances I have remarked it to 

 be even obsolete. 



From the exceedingly variable P. sphinctostoma the lau- 

 rinea differs mainly in its sliorter, obtuser, and relatively 

 broader form, and in its colour being of a clearer olivaceous 

 brown, with the volutions (which are rather more striate) appre- 



