'JJ.ADE1RAN GROUP. 279 



Habitat Maderam borealem ; in humidis sylvaticis rarissi- 

 mum. Sed ad Canical in statu semifossili sat copiose invenitur. 



As already implied, the present Craspedopoma is more 

 strictly Trochiform than the preceding one, its more conical 

 upper and more flattened under portions (shaping the ultimate 

 whorl into a much sharper keel), added to its altogether more 

 compact and flatter volutions and the peculiar distortion (to 

 which I have already alluded) about the aperture, giving it a 

 very singular appearance. Its colour too is exceedingly remark- 

 able, being either of a straw-yellow with slightly darker (but 

 irregular) spiral hair-like lines, or else of a dull coffee-brown 

 with the spiral lines of a paler tint. Its sculpture is coarser 

 than that of the G. Lyonnetiamim, the minute closely-set 

 spiral costse being more distinct. 



The C. trochoideum is much rarer than its ally, being de- 

 cidedly a scarce species. So far as has been observed hitherto, 

 it is confined to the damp wooded ravines in the north of Ma- 

 deira proper (such as the Ribeira do Inferno, the Ribeira Funda, 

 the Ribeira de S. Jorge, and the Boa Ventura), where it has 

 been met with by Mr. Leacock, Sr. Moniz, and others. In the 

 subfossiliferous deposits, however, at Canical, it is comparatively 

 abundant (where it was inadvertently identified by Mr. Lowe 

 with the C. Lyonnetianum), a fact which would seem to imply 

 that it may formerly have been a dominant species in the 

 Madeiran fauna. 



Pam. 2. TRUNCATELLID.E. 

 Genus 2. TRUNCATELLA, Risso. 



Truncatella truncatula. 



Cyclostoma truncatulum, Drap., Hist. Nat. des Moll. 40 



t. 1. f. 28-31 (1805) 

 Truncatella truncatula, Lowe, Zool. Journ. v. 302. t. 13. 



f. 13-18 (1835) 

 Id., Proc. Zool. Soc. Lond. 217 



(1854) 

 Paiva, Mon. Moll. Mad. 162 



(1867) 



Watson, Journ. de Conch. 220 



(1876) 



Habitat Maderam ; sub lapidibus sestu maris quotidie sub- 

 mersis, hinc inde una cum Pedipedibus, Auriculis, Melampi- 

 dibus(\u.Q occurrens. 



The European T. truncatula (so remarkable for the apically 



