392 TEST ACE A ATLANTICA. 



sharply carinated form, its acutely angulated aperture, and its 

 rather thin, subpellucid substance. Its keel is broadly com- 

 pressed^ both above and below, and is more or less traceable up 

 the spire, — forming often on the penultimate whorl a narrow 

 line overhanging the suture ; its volutions are flattened ; and its 

 surface is of a pale clear whitish-brown, merging beneath into 

 a brownish-white. In size it is a little larger than the afficta 

 (measuring about 6^ lines across its broadest part), but smaller 

 than the discobolus ; its umbilicus is a trifle wider than that of 

 the former, but narrower than that of the latter ; and its 

 ultimate whorl hardly descends at all anteriorly. 



Helix afficta. 



Helix afficta, Fer., Prodr. 151 (1821) 



„ „ (pars), Mouss., Faun. Mai. des Can. 65 



(1872) 

 „ „ (pars), Pfeif., Mon. Hel. vii. 296 (1876) 



Habitat Palmam ; hinc inde sub lapidibus in intermediis. 



As already mentioned, the present Helix may be regarded 

 as the Palman representative of the H. discobolus of Gromera, 

 and of the H. 'planaria of Teneriffe, — though it is certainly 

 more allied to the former than to the latter. With the H. 

 discobolus indeed it has very much in common, — agreeing with 

 it in its general sculpture and surface, and in its volutions not 

 being so extremely flattened as in the planaria ; nevertheless it 

 differs in its smaller size and considerably narrower umbilicus, 

 and in its whorls being 6^ in number instead of 7. 



From the H. planaria the afficta recedes in being more 

 solid, and very much less depressed both above and below, in its 

 umbilicus being appreciably smaller, in its keel being very 

 much less broadly flattened out, and iu its aperture being much 

 less angulated externally. 



It was in the intermediate districts of Palma that the H. 

 afficta was met with by Mr. Lowe and myself, particularly 

 in the Barranco de Nogales ; and it appears to have been found 

 in the same island by Blauner. 



Helix gomerae, n. sp. 



T. umbilicata, lenticularis, acutissime carinata, tenuis, 

 subopaca, densissime et minute costulato-striata, pallide cornea ; 

 spira obtuse convexiuscula ; anfractibus 6^, lente crescentibus, 

 ultimo (supra et infra) ad carinam subalbidam anguste leviter 

 compresso, antice breviter deflexo, subtus subconico-convexo ; 

 apertura obliqua, securiformi, peristomate acuto, marginibus 

 subapproximatis et lamina subnulla junctis, columellari an- 



