862 TEST ACE A ATLANTIC A. 



shining and comparatively unsculptured. Its aperture is large, 

 with the upper and lower portions wide apart and disconnected ; 

 and its peristome, although recurved, is narrow and only slightly 

 expanded. 



When young and undeveloped the H. Pkdonia is very much 

 more sharply carinated (on account of the ultimate, unkeeled 

 volution having still to be added) ; and, according to Mousson 

 (for the example now before me does not shew it), there are a 

 few hair-like filaments arising out of the asperated granulations. 

 If this latter statement be true, it would seem to imply that the 

 real affinities of the H. Plutonia are not with the exact forms 

 amongst which I have placed it, and with which it is associated 

 by Mousson. But, in point of fact, the species is a very diffi- 

 cult one as regards location ; and what its nearest allies may be, 

 it is by no means readily apparent. 



Helix seinitecta. 



Helix semitecta, 3Iouss., Faun. Mai. des Can. 75. pi. 4. 



f. 17 (1872) 

 „ „ Pfeif., Mon. Hel. vii. 423 (1876) 



Habitat Gomeram, semifossilis ; collegit cl. Fritsch. 



A Helix which was found by Fritsch in Gomera, and ap- 

 parently in a subfossil condition ; though as it was sufficiently 

 well preserved for Mousson to give some idea both of its colour 

 and markings, it can scarcely have been so strictly subfossilized 

 as many of the species which we have had occasion to 

 notice. 



The H. semitecta seems, judging from the diagnosis and 

 figure, to be distinctly umbilicated, — the umbilicus however 

 being half closed over by the expanded lamina of the lower lip ; 

 in outline it is rather convex, obtuse, and compact, and without 

 any traces of a keel ; its surface is not only strongly and regu- 

 larly striated, but likewise unequally beset with coarse granules ; 

 and its aperture is relatively rather small, with the upper and 

 lower margins of the peristome a good deal, and subequally, 

 curved. * La coloration,' says Mousson, ' ne se compose pas de 

 zones continues simples, mais de 4 fascies, qu'interrompent des 

 taches anguleuses blanches, qui se continuent sur les intervalles ; ' 

 and, as regards size, it would appear to measure about 1 1 lines 

 across its broadest part. 



Helix Paivana. 



Helix Paivana, Morelet [nee Lotue 1 , Journ. de Conch, xii. 1 86 

 (1864) 

 „ „ Mouss., Faun. Mai. des Can. 77 (1872). 



„ „ Pfeif., Mon. Hel. vii. 455 (1876) 



