68 THE MOLLUSCA OF THE FIRTH OF CLYDE, 
ing species at Battery Point. Mr. Norman has taken it 
plentifully, but of small size, at the Outer Allans, Millport. 
British distribution.—From Shetland to the Channel 
Islands; a local species, but abundant were found. 
Foreign localities—Lerici and Nice are given by Mr. 
Jeffreys. I have not noticed it in any of the lists which I 
have examined. 
FAMILY SKENEIDA, Clark. 
SKENEA, Fleming. 
* Skenea planorbis, O. Fabricius. 
Turbo planorbis, Fabricius ; Helix depressa, Montagu ; 
Turbo depressus, Maton and Rackett; Skenea depressa, 
Fleming ; Delphinoidea depressa, Brown. 
Habitat—In rock pools between tide marks, on small 
seaweeds, and under stones. Exceedingly abundant at 
Cumbrae, and very common throughout the whole district. 
British distribution.—On all our coasts on stony and 
rocky shores; very common. 
Foreign localities. — Iceland (Verkriizen and others), 
Spitzbergen (Torell), Norway and Sweden (Lovén and 
others), France (Macé), Mediterranean (Jeffreys and others), 
Madeira (Watson). In America it extends from Greenland 
(Fabricius) to Massachusetts (Gould) as S. serpuloides. 
HomMALoGyra, Jeffreys. 
* Homalogyra atomus, Philippi. 
Truncatella atomus, Philippi ; Helix nitidissima ? Adams ; 
Skenea nitidissima, Forbes and Hanley. 
Habitat—Under stones at the lowest verge of spring 
tides and on seaweed and Zostera down to a few feet below 
that mark. It is probably a very common species, but the 
only localities I have noted are Farland and Battery Points, 
in Cumbrae. 
British distribution—From Shetland to the Channel 
Islands nearly everywhere, and generally abundant. 
Foreign localities—From Norway throughout all the 
western coasts of Hurope, and on both sides of the Mediter- 
ranean. 
Homalogyra rota, Forbes and Hanley. 
Skenea rota, Forbes and Hanley. 
Habitat—Mr. Robertson has taken this species in 6 or 8 
