332 NATICID^. 



The outer lip arches downwards, so as to form an acute 

 angle, at its superior junction, with the body. The uni- 

 bihcus, which is environed by a narrow strip of colour 

 (chestnut, brown, tawny, or chocolate), adjacent to which 

 the surface is whitish or paler than usual, is simple, smooth 

 internally, moderately large, yet in some slight degree (in 

 the young almost entirely) narrowed by the enamel of the 

 inner lip, which, as it diverges thence, runs to the columella 

 in a much more slanting line than in the preceding species, 

 consequently its angle is much more obtuse and less de- 

 cided. The pad of enamel which strengthens the outer 

 lip, at its origin, is white ; the rest of the callus of the 

 inner lip (it is rather thickly yet not very broadly spread) 

 is sometimes white, sometimes stained with livid brown. 

 The pillar is pure white, solid, and greatly rounded at its 

 basal union with the opposite lip. A fine example 

 measured ten lines in length, and two less in breadth.'" 



The species abounds on most sandy shores, where at low 

 water it may be detected by the little hillock of sand 

 under which it has buried itsolf 



By a most interesting suite of examples, Mr. Jeffreys 

 has clearly demonstrated to us that the Nerita nitida -f- of 

 Donovan is merely a milk-white variety of this species. 

 As the links or intermediate examples are rarely to be 

 obtained, we mention the two most important. The first 

 differs from the typical Alderi in being of a paler hue, with 

 an opaque white band beneath the sutures ; here and there 



* It is just possible that the Nerita Icevida, thus briefly described by Laskey 

 in the " Memoirs of the Wernerian Society" (vol. i. p. 409), may be a variety of 

 tliis shell : " Bears some resemblance to (jluucina, but has a more produced apex, 

 and is divested of the markings of that shell." 



+ A little West Indian species, the Natica acuta of Philippi (Wiegm. Archiv. 

 Naturg. 1045; Neue Conch, vol. ii. p, 41, Nat. pi. 2, f. 3, altered to Philippiana, 

 Nyst, in the Index ; perhaps the lactea of Guilding, Tr. Lin. xvii. p. 31), is 

 occasionally so named in collections, and in all probability was what Montagu 



