CANARIAN GROUP. 351 



growth; and such being the case, its affinities, which at first 

 sight are not readily apparent, will perhaps be ascertained to 

 lie amongst the forms around the H. jjloMorhella, — though, at 

 the same time, the species has evidently something in common 

 with the (equally Palman) H. f/ranoinalleata. 



Not to mention this peculiarity of its umbilicus, the pre- 

 sent species is smaller than the H. granornalleata, and it is 

 also rather more depressed both above and below, and it has a 

 fine thread-like though minute keel which is traceable even down 

 to the very aperture. It is not much malleated, — its sculptiue 

 consisting mainly (apart from the excessively minute sand- 

 like granules) of extremely iiTegular and densely-packed, coarse, 

 subconfluent, oblique ridges, or subundulating vermiform folds ; 

 and in colour it would seem to be of a dingy olivaceous-white, 

 suffused with a darker tint in consequence of the 4 or 5 obso- 

 lete bands which are indistinctly indicated. 



Helix Plutonia. 



Helix Plutonia, Lovje,A,in. Xat. Hist %-ii. 108 (1861) 

 „ „ Pfeif., Mon. Hel. v. 300 (1868) 



„ „ Afouss., Faun. Mai. des Can. 76. pi. 4. 



f. 12, 13 (1872) 

 „ „ Pfeiff., Mon. Hel. \di. 423 (1876) 



Habitat Lanzarotam, et Fuerteventuram ; in ilia recens, sed 

 in hac et recens et vix semifossilis ad Pozonegro parce reperitui-. 



By M. Fritsch this well-marked Helix was found both in 

 Lanzarote and Fuert event m-a, but it is only in the latter 

 that it was obtained by Mr. Lowe, -who took several subfos- 

 silized examples of it (for I think that they are more than 

 merely dead and bleached), along with one or two others im- 

 mature and recent, at Pozonegro, on the eastern side of that 

 island ; but it is a species which I did not myself meet with. 



The H. Plutonia is a large, rather flattened, obtuse, 

 and almost sublenticular shell, nevertheless with the nucleus 

 of the extremely compact and closely-set spire somewhat pro- 

 minent, and with scarcely any indications of a keel on the 

 ultimate volution, though there are evident traces of one up 

 the spii-e, — manifested by a thread-like, subelevated, laterally- 

 compressed line along the anterior edge of the sutiue. Its 

 umbilicus is generally half-exposed, and thus far therefore 

 open, but at times it is nearly closed up by the reflexed lamina 

 of the coliunella ; its whorls are six in number, and all of them 

 except the basal one much flattened ; and its upper surface is 

 covered with fine and light, irregular, scabrous, costate lines, 

 intermingled with a few granules, whilst, beneath, it is more 



