278 TEST ACE A ATLANTIC A. 



Cyclostoma Lyonnetianum, Lowe, Ann. Nat. Hist. 117 



(1860) 



Craspedopoma Lyonnetianum, Paiva,Mon. 31 oil. Mad. 159 



(1867) 



Habitat Maderam ; in umbrosis humidis sylvaticis inter- 

 na ediis, liinc inde ad rupes irriguas, sat vulgaris. 



This species and the following one are on a smaller and 

 more jTroc^us-shaped tjrpe than the preceding two ; and their 

 basal volution is on a different pattern, — it being not only more 

 distinctly keeled, but also somewhat unduly enlarged (or up- 

 wardly widened) towards the aperture, which gives that par- 

 ticular region a rather distorted appearance, causing the suture 

 to be upwardly curved, and diminishing the breadth at that 

 point of the penultimate whorl. This configuration of the basal 

 volution is carried out on a very much larger scale, and to an 

 exaggerated extent, in the Bulimus Lyonnetianus, Pallas, from 

 the Mauritius, — a fact which suggested to Mr. Lowe the trivial 

 name of the first-discovered (but unfortunately the least charac- 

 teristic) of these two Madeiran Craspedopomas. 



The C. Lyonnetianum is considerably smaller than the G. 

 Monizianum ; and it varies in hue from a dark uniform coffee- 

 brown (which would seem to be normal) into a yellowish sienna, 

 both states being occasionally blotched with patches and streaks 

 of a pale straw-colour. The spire is proportio7iately more 

 drawn-out or produced, the peculiar construction of the ultimate 

 whorl causing it sometimes to appear a little eccentric or tilted ; 

 and its sculpture is close and somewhat coarse, the minute spiral 

 subundulating lines being more appreciably developed than is 

 the case in either of the preceding species. 



The present Craspedopoma, which is confined to the damp 

 wooded ravines of Madeira proper, was first detected by myself 

 towards the head of the Ribeira de Sta. Luzia, — where it is 

 abundant, amongst loose friable soil and vegetable detritus, at 

 the base (and on the ledges) of the lofty perpendicular rocks, in 

 company often with the C. lucidum and various Pupai ; and it 

 has been taken also in the Eibeira do Inferno, in the north of 

 the island, and likewise (according to the Baron Paiva) in the 

 Eibeiro Frio. 



Mr. Lowe stated that the C. Lyonnetianum is common in a 

 subfossil condition at Canifal ; but this was an error, the 

 Cauipal species being unmistakeably the C. trochoideum. 



Craspedopoma trochoideum. 



Cyclostoma trochoideum, Loiue, Ann. Nat. Hist. 117 (1860) 

 Craspedopoma trochoideum, Paiva, Mon. Moll. Mad. 159 



(1867) 



