60 THE MOLLUSCA OF THE FIRTH OF CLYDE. 
Foreign localities—Iceland and Spitzbergen to Norway 
and western Europe as far south as the Bay of Biscay. In 
America it is on record from Massachusetts as Lacuna 
neritoidea (Gould), which (fide Jeffreys) is our species. 
LiITTORINA, Férussac. 
* Littorina obtusata, Linné. 
Turbo obtusatus, Linné; Turbo neritoides, Pulteney (not 
Linné); Turbo retusus, Lamarck ; Littorina littoralis, 
Forbes and Hanley. 
Habitat—F rom half-tide down to low water, exceedingly 
abundant on all stony beaches, and on the Fuci which cover 
rocky coasts, especially on Fucus serratus and F. vesiculosus. 
The colourings are very varied, plain orange yellow and 
olive green being the rule; but these are frequently diver- 
sified by bands and tesselated markings of various shades of 
brown and red. 
British distribution.—On all our coasts ; very common. 
Foreign localities—The following are given (with cer- 
tainty) in Brit. Con.:—Iceland, Farées, White Sea, Scandi- 
navia, Heligoland, Holland, France, Spain, Agores, Malaga, 
Corsica; whilst various other Mediterranean and Adriatic 
localities are given with doubt. 
Littorina neritoides, Linné. 
Turbo neritoides, Linné; Turbo petrzeus, Montagu ; Turbo 
coerulescens, Lamarck ; Littorina petreea, Brown. 
Habitat—Mr. Norman records this species as abundant 
on the Outer Allans, Millport Bay, and not uncommon 
elsewhere in the Firth, and it is here included on his 
authority alone. Mr. Robertson has not met with it, nor 
have I, although I have made diligent search. It is a local 
species, and dwells on rocks above high water mark. 
British distribution.—Locally abundant on most of our 
coasts from the Channel Islands to Shetland. 
Foreign localities—From Norway (Lovén), throughout 
Western Europe, and as far as the Canary Islands. It fre- 
quents both sides of the Mediterranean, the Aigean, and 
Black Sea. 
* Littorina rudis, Maton. 
Turbo rudis, Maton ; Nerita littorea, Fabiicvus (probably) ; 
Littorina Greenlandica, Menke. 
Habitat—Abundant between tide marks throughout the 
Clyde district. In winter and early spring they congre- 
