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MACTRA. ae 
but is very scarce. The variety truncata is common at low 
tide in most of the sandy bays in Bute and Cumbrae; and 
the variety elliptica is by no means scarce in muddy sand 
and gravel in from 12 to 30 fathoms on the Ascog shore, 
Bute ; outside the Tan Spit, Cumbrae; and off Otter Spit, 
Loch Fyne. 
British distribution.—Nearly everywhere ; the variety 
elliptica ranging from 10 to 100 fathoms, whilst the type 
and variety truncata are littoral, or nearly so. 
Foreign localities (type).—Iceland (Verkriizen), Holland 
(Herklots), Spain (M‘Andrew), Mediterranean and Adriatic 
(Danilo, and others). The variety ellipticuw ranges from 
Iceland (Verkriizen) to northern Spain (M/‘Andvew). 
* Mactra subtruncata, Da Costu. 
Trigonella subtruncata, Da Costa; Mactra deltoides, Lamareh; 
Mactra stultorum, Pennant (not Linné). 
Habitat—Exceedingly abundant a little above low water 
in Ettrick and St. Ninian’s Bays, Bute; and in Fintry Bay, 
Cumbrae. It is common also all along the Ayrshire coast, 
and in most sandy bays throughout the district. In 
Cumbrae they are known as “Aikens,” and are used both 
for food and bait. This species is a favourite dish with 
Purpura lapillus, whose presence in considerable numbers 
in such an uncongenial spot as the sandy bay of Fintry is 
probably caused by the abundance of these Mactrze, on which 
they feeds I observed that, although the “Aikens” were in 
thousands, two of the carnivora frequently attacked opposite 
sides of the same bivalve. I also noticed here a singular 
case of derective instinct in a Purpura, which was diligently 
piercing a hole ina single valve (a much worn one too) of 
Mactra, and had nearly completed its task when interrupted. 
Dr. Landsborough says that this species goes by the name 
of “Mureck Baan” in the Highlands, and states that “it is 
probable that Mureck is the Celtic origin of the Latin Murex, 
the shell-fish which yielded the Tyrian dye or Imperial 
purple,’ a philological opinion which will at least satisfy 
Professor Blackie, if no one else. Maorach Baan simply 
means a white shell, and is applied indifferently to several 
species—including Mya arenaria.+ 
+ Slige, not Maorach, is the word used by Ossian’s heroes when they 
proposed a carouse in the ‘‘ Hall of Shells.” Fingal is often called Righ nan 
slige fiul, ‘‘ King of the festive shell,” s/ige being a deep, big-bellied shell 
suitable for a demi-god’s potations. 
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