270 TEST ACE A ATLANTIC A. 



as a little less ovate (or more strictly fusiform), and one which 

 occurs under a slightly different aspect both at Madeira and the 

 Salvages, the examples from the former (which I have treated 

 as the normal ones) being a trifle broader and more ventricose 

 than those from the latter, as well as (on the average) darker 

 in hue and with a much more decidedly purple tinge. In both 

 phases however the outer lip of the peristome is totally simple 

 (or unarmed), and the upper of the two ventral plaits is re- 

 duced greatly in dimensions, being more often represented 

 by a minute isolated tubercle. The entire shell is somewhat 

 less solid (at any rate when immature) than that of the 

 cequalis ; and it is usually subopake (though a few of the 

 comparatively pallid ones from the Salvages are often a little 

 shining), as well as rather more evidently striated (especially 

 in front), and with more appreciable traces of a series of small 

 impressions or pits arranged in a spiral line at a certain dis- 

 tance behind the suture. This last is more sunken (or less 

 superficial) than in the cequalis, the whorls are not quite so 

 flattened, and the apex of the spire is not only more acute but 

 very frequently tilted or eccentric. 



From the Mediterranean A. myosotis, Drap., which it some- 

 what resembles (so far at least as I understand that species) in 

 the number and proportions of its plaits, it differs in being 

 smaller and relatively less elongated, as well as more solid and 

 more opake, in the volutions of its spire being a little shorter 

 and less convex, and in its aperture being narrower and less 

 largely developed. 



I have named this Auricula after the Eev. E. B. Watson, 

 whose elaborate investigations on the Madeiran Mollusca, par- 

 ticularly the marine departments, have contributed so much to 

 our knowledge of the fauna, and to whom I am also indebted 

 for much valuable information concerning the Terrestrial 

 species. 



Auricula gracilis. 



T. fusiformis (sc. precedent! forma fere similis, sed minor et 

 vix subgracilior), sensim minus solida, subnitida, saepius cas- 

 taneo-fusca et plerumque subpurpureo-tincta ; apertura plicis 

 3-4 albidis (superiore ssepius obsoleta, secunda semper parva 

 subtuberculiformi, tertia magna intrante, et quarta columellari 

 contorta) instructs, ; peristomate recto, acuto, margine dextro 

 denticulis 1-5 intus armato (rariss. simplici). Long. lin. 2-J 3 ; 

 diam. maj. 1^-. 



Melampus gracilis, Lowe, Zool. Journ. v. 288 (1835) 

 Auricula gracilis, Id., Proc. Zool. Soc. Lond. 217 (1854) 



