50 THE MOLLUSCA OF THE FIRTH OF CLYDE. 
the thick stalks of the sea-weed, whilst the young, thin 
individuals are generally on the fronds and amongst the 
roots, but not imbedded. ‘The variety levis I have taken 
at Campbeltown Loch, north shore. 
British distribution.—Every where on Laminarize. Very 
common. 
Foreign localities —From Iceland (Verkriizen) and Nor- 
way (Lovén) throughout Western Europe, and as far South 
as Mogador (Andrew); “Sicily (Maravigna)” is given in 
Brit. Con. 
TECTURA, Cuvier. 
Tectura testudinalis, Miiller. 
Patella testudinalis, Miiller ; Patella Clealandi, Sowerby ; 
Lottia testudinalis, Forbes ; Acmeea testudinalis, Forbes 
and Hanley. 
Habitat—On rocks and stones from a little above low 
water down to 6 or 8 fathoms; common. LEspecially abun- 
dant between tide marks on the east side of Ardbeg Point, 
Rothesay Bay, and near the new pier at Craigmore, and 
more or less common all round Bute, as well as through- 
out the district. Considerable varieties of colouring are 
met with, ranging from a dirty white to dull uniform 
brown, the standard being of course a greyish body-colour, 
streaked, tesselated, and blotched with brown. 
British distribution—Throughout the North and West 
of Scotland, and the Irish Sea as far south as Dublin 
Bay. On the East coast it has been found at intervals as 
far south as Yorkshire and the Dogger Bank (Leckenby 
and Marshall), but I do not know whether it is plentiful or 
not. This species is more at home in the northern and 
western portions of these islands than elsewhere ; indeed, 
the knowledge of its existence on the eastern coasts of 
England is quite recent, and this has been considered a 
sufficient reason for coming to the conclusion that a rapid 
southern migration has taken place on that seaboard. 
Foreign localities—Norway and Sweden (Lovén, and 
others), Iceland (Verkriizen), Greenland ( Wallici), Labrador 
(Whiteaves), St. Lawrence (W. Brown), Massachusetts 
(Gould). 
* Tectura virginea, Miiller. 
Patella virginea, Miiller ; Patella parva, Da Oosta; Patella 
pulchella, Forbes ; Acmeea virginea, Forbes and Hanley. 
Habitat—Very common on hard ground, adhering to 
