iso 



TESTA CEA A TLAXTICA. 



by Mousson in his late ' Revision ' under the trivial name of 

 canariensis. In its pallid hue and nearly opake, well-nigh un- 

 sculptured surface the species agrees with the more northern H. 

 siiuilis, Drap., "which occurs also in the Madeiran Group ; never- 

 theless in every other particular it is totally different, — its larger 

 size and much more elongate and conical outline, added to its 

 more numerous and less ventricose volutions and its less rounded 

 aperture, the peristome of which is less elevated and less con- 

 spicuously continuous across the ventral region of the basal 

 whorl, removing it altogether from that species. 



CANARIAN CATALOGUE. 



