Our commonest littoral species, on rocky ground. In July, 1808, 
two young specimens of this species were found alive on the rocks 
in Cullercoats Haven, which were completely decorticated. ‘-It is 
very unusual for such young (living) individuals to be decorticated. - ’ 
— R. Home. 
T. ziz yi’uinus, and var. lyonsii, Linn. 
Common. Frequently found in the crab pots. 
Family — Littorinide. 
( lenus — L acuna. 
L. DIVARICATA, Fabr. 
L. rincta , F. and II. 
Not uncommon, on the fronds of Laminaria diyitata. 
Genus — Littorina. 
L. obtusata, Linn. 
L. return, Lam. 
Very common in rocky pools. An extremely favourite habita- 
tion ot hermit crabs. Very variable in colouring. The eggs are 
often found, at any time of the year, on the fronds of Fueus 
resiculosus surrounded by a gelatinous fluid. 
L. rudis, Mat. 
Including /.. nultlmima, Beau, and L. neylecta, Beau. 
Very common, on rocks and cliffs at and even above high water 
mark, where it is only covered by high tides. 
L. litokea, Linn, (the common periwinkle). 
Very common in some places, as at Budle Bay and Fenham 
Flats, but not very common at Cullercoats. 
Genus — Rissoa. 
R. parva, and var. interrupta, Da Costa. 
Including R. interrupta, Adams. 
Common, in shell-sand. 
R. MKMBRANACEA, Adams . 
R. labiosa, F. and II. 
R. pul la, Brown. 
One specimen (dead, but not worn) was taken off Dunstanboro’ 
in September, 1 807. Mr. lb Howse says it is “ probably a ballast- 
shell, as it is not known” (?) “in the North Sea.” As Capt. Brown 
found it “on the sands at Holy Isle” (Br. Conch. Illus. 18, t. 8, 
f. 25), it may surely be included as a very rare Northumbrian 
species. 
