OF NORTHUMBERLAND AND DURHAM. 151 
band in front of the foot by which our species is distinguished, 
and his description altogether corresponds more nearly with that 
of ZL. rudissima. 
Philippi enumerates seven synonyns of this species, without 
taking into account our English name, and the Z’urbo neritoides 
of Linnzeus with which he is now inclined to indentify it. 
The Turbo ziczac found by Lady Wilson near Sunderland, 
and stated to differ from the West Indian specimens in wanting the 
ZICZAC markings, is most likely only a variety of this species ; at 
least a specimen so named in the cabinet at Wallington, which 
we had the opportunity of examining through the kindness of 
the late Sir John Trevelyan, Bart., certainly belongs to ZL. 
petroed. 
6. L. retusa, Lam. 
Nerita littoralis, Mont. Test. Brit. 467. 
Littorina neritoides, Johns. in Berw. C. Proc. i. 269. 
On sea-weeds, among the rocks near high-water mark, common. 
The Zurbo retusus and 7’. neritoides of Lamarck, are un- 
doubtedly only different forms of the Nerita littoralis of Lin- 
nexus, as we have satisfied ourselves by an examination of the 
Lamarckian specimens. As 7’. neritoides, Linn., is not considered 
to belong to this species, we adopt the former name. 7’. obtu- 
satus, Linn., we are assured by Mr. Hanley, is distinct. 
The Turbo aureus of Brown (Conch. Ilust. 2nd Ed. 17, t. 10, 
f, 23), found by Sir Walter C. Trevelyan, Bart., at Seaton, Nor- 
thumberland (qu. Durham 2), is referred in the appendix to the 
genus Margarita, and in the description of the plates is called a 
LInttorina. We think it scarcely belongs to either of these 
genera. 
51. LACUNA, Turton. 
1. L. paturpuna, Da Costa. 
Nerita pallidula, Mont. Test. Brit. 468. 
On sea-weeds between tide-marks, not uncommon. 
2. L. puteona, Zurt. 
Lacuna puteola, Turt. in Zool. Jour. iii. 191. 
On sea-weeds and in shell-sand, rather rare. 
