CANARIAN GROUP. 415 



currens. Semifossilis in calcariis inter urbem Las Palmas et 

 Puerto da Luz parce reperitur. 



The H. lemniscata is one of the most distinct and elegant 

 of the Canarian Helices, and confined, so far as I have myself 

 observed, to Grand Canary, — where it is rather common 

 throughout the intermediate district of El Monte, ascending- 

 even to the Eoca del Soucilho ; and it was found in the same 

 island by Messrs. Webb and Berthelot, Grasset, Fritsch, and 

 Watson. Indeed in an old memorandum of Mr. Webb's which 

 is now before me, it is stated to occur likewise in the south of 

 Teneriffe ; but as Webb was not always very accurate as regards 

 his localities, this habitat certainly requires further corrobora- 

 tion. In Grand Canary I met with it also in a genuinely sub- 

 fossil condition, namely in the calcareous deposits between Las 

 Palmas and the Puerto da Luz. 



In the slight prolongation of its axis, as it were, in a straight 

 line (giving to the aperture a rather peculiar form), the H. 

 lemniscata differs from the immediate species with which I 

 have associated it ; nevertheless there can be little doubt of its 

 no distant affinity with the H. Michaiuli and galeata of the 

 Madeiran Group, and (though somewhat less perhaps) with the 

 Canarian species around the //. persimilis and phalevata. 

 Apart from its rounded-pyramidal, or turbinate, outline, it may 

 be defined as a thin shell, of a rather lively hue, — many suf- 

 fused tints, not easily to be expressed, being blended over its 

 surface. Its ground-colour is more often of a yellowish or cine- 

 reous white (not unfrequently with a faint lilac tinge) ; and 

 there is a single, well-defined, continuous, purplish-brown band 

 on the underside, below the keel, which becomes lost within the 

 aperture ; whilst a second is placed immediately above the keel, 

 and runs alongside the suture to almost the apex, — becoming- 

 more and more interrupted, or broken-up, in its course. The 

 peristome (which is acute, and not thickened into a corneous 

 rim) is generally somewhat flavescent ; its perforation is minute, 

 and well-nigh concealed ; and its volutions (which are about 6^ 

 in number, and a good deal flattened) are strongly sculptured 

 with the oblique, irregular lines of growth. When immature 

 the H. lemniscata is more decidedly keeled. 



Genus 10. BULIMUS, Scopoli. 

 (§ Coehlicella, Risso.) 



Bulimus ventricosus. 



Bulimus ventricosus, Drap., Tabl. de Moll. 68 (1801) 



v » 



Id., Hist. Nat. 78. t. 4. f. 31-33 (1805) 



