136 THE NAUTILUS. 



nearly always present, but on the Ilheo de Baixo, on Jan. 22, I 

 found a creamy-white bandless variety, which may be called 

 var. lactescens. This form was also known to Wollaston. The 

 distribution of H. punctulata is peculiar. It has not been re- 

 corded from Madeira, but a rather small and peculiar race 

 (avellana Lowe) occurs both living and fossil on Bugio, the 

 southernmost of the Desertas. At the fossil-beds near Canigal, 

 Madeira, however, I found a specimen of undoubted P. punctu- 

 lata, measuring 13 by 14 mm., thinner than bowditchiana, and 

 still showing faint traces of the bands. It has a recent appear- 

 ance, and may not be truly fossil. Whether P. punctulata really 

 lived in Madeira, may still remain somewhat uncertain, as 

 Baring and Ogilvie Grant (Zoologist, Nov. 1895) report finding 

 seven whole H. pisana in the stomach of a kestrel, and it is 

 conceivable that an owl pellet might contain an unbroken snail 

 shell. 



The P. punctulata in Porto Santo suffer severely from an 

 enemy, the broken shells being found very commonly under 

 rocks. From the position of these remains, it was impossible 

 that the enemy should be a bird, and the small lizards (Lacerta 

 dugesii) so common under the rocks probably could not break 

 the shells. Baring and Ogilvie Grant (loc. cit.) speak of the 

 great spider of Porto Santo (Lycosa madeirana Walck. ) as feed- 

 ing on snails, and I have no doubt that this is the mysterious 

 enemy of P. punctulata. In the face of such an enemy, P. bow- 

 ditchiana, with its large and thick shell, would have a great ad- 

 vantage over its smaller relative. 



The common P. vulgata (Lowe) of Madeira has the same 

 white mantle, and is evidently strictly congeneric. According 

 to Pilsbry this is the real nitidiuscula of Sowerby, though not 

 that of Wollaston. The soft parts of vulgata from Funchal were 

 described as follows : 



Animal with foot broad, white ; tentacles black ; dorsal side 

 of head and neck very dark, abruptly contrasting with the 

 white foot ; mantle opaque white. The habits of vulgata seem 

 to be much like those of punctulata, though it is perhaps less 

 retiring. There is a large Lycosa (L. blackwallii Johnson) in 

 Madeira, which may prey upon it but it seems to be absent from 

 the lowlands about Funchal, where P. vulgata abounds. 



