150 CATALOGUE OF THE MOLLUSCA 
respect it is extremely variable, and is sometimes quite smooth. 
It undergoes all the varieties of colour and banding found on the 
last species, besides which we have obtained, at N ewbiggin, a 
black, and a tessellated variety, coming so near to Z. tenebrosa, 
that we hesitate to call them distinct. The latter is generally 
found in mud, but we are inclined to think that the Turbo 
tenebrosus, and 7’. jugosus of Montagu are probably the two ex- 
treme limits that this very variable shell undergoes, 
4, L. neauecra, Bean. 
Intiorina saxatilis, “ Bean,” Johns. in Berw. C. Proc. i., 268. 
Littorina neglecta, Bean, in Thorpe’s Brit. Mar. Conch. 266. 
On rocks near low-water mark, bare of sea-weed, but covered 
with Balani and muscles. 
The habitat of this little species is different from that of the 
preceding, being always nearer low-water mark. This, with the 
difference of form and size, induces us to think it distinct. 
We have taken from the body of this species, embryos, well 
developed and covered with a shell —A. ZH. 
It was first described by Dr. Johnston under the name of 
saxatilis, given it in manuscript by Mr. Bean. In consequence 
of this name having been used by Olivi for another species (pro- 
bably the following), Mr. Bean subsequently changed it to 
neglecta, under which name he has described it among his new 
species in Thorpe’s “ Brit. Marine Conchology.” Having omitted 
to mention that it had been described before, the species appears 
twice in that work :—viz., under the name of Z. saxatilis, in the 
Addenda, and of Z. neglecta, in the Supplement. 
5. L. petrma, Mont. 
Helix petrea, Mont. Test. Brit. 403. 
Turbo cerulescens, Lam. Anim. s. Vert. 2nd Hd. ix. 217. 
On rocks at and above high-tide level, frequent, especially in 
crevices of the cliffs, where it nestles in company with L. rudissima, 
beyond the reach of the sea, excepting the dashing of the spray, 
and the high water of spring tides. 
There can be little doubt that the 7’. cewrwlescens of Lamarck, 
of which we have specimens from two localities in the Mediter- 
ranean, is a variety of this species, though Philippi, in his 
description of the animal, does not mention the milk-white 
