MACTRA. 421 



ral teeth of the present species ; it is analogous to the 

 variety elliptica of M. solida. Mr. Alder also mentions, 

 in his ( Catalogue of the Mollusca of Northumberland 

 and Durham/ " a thinner variety from deep water." M. 

 subtruncata is not uncommon in our newer tertiaries as 

 far back as the Red Crag. It ranges from East Fin- 

 mark (Danielssen), throughout the North Atlantic, to 

 Gibraltar (M { Andrew), both sides of the Mediterranean 

 to Sicily (Scacchi and others), and to the Black Sea (Mid- 

 dendorff), at depths varying in each of these tracts from 

 the shore-line to 40 fathoms. Brocchi has recorded it 

 among his Subapennine fossils, and Philippi from the 

 Sicilian tertiaries j and I found it in the Uddevalla beds, 

 and at Biot near Antibes in upper miocene strata. 



A small variety is gathered alive at low water in 

 Lamlash Bay to feed pigs. (Alder.) According to Mr. 

 Hyndman this species is called the " Lady-cockle " at 

 Belfast. Mr. Norman says that it goes by the name of 

 " Aikens " in the Clyde district, where it is frequently 

 used as bait, and for that purpose either raked up from 

 the sands at low tides or gathered by the hand when 

 thrown up on the beach by storms. In Dr. Lands- 

 borougrVs agreeablv written ' Excursions to Arran ' it 

 is stated that the last-mentioned name is " confined to 

 the Lowlands ; in the Highlands it is called ' Mureck- 

 baan/ — baan signifying the colour, which is white, and 

 Mureck (it is probable) being the Celtic origin of the 

 Latin Murex, the shell-fish which yielded the Tyrian 

 dye or imperial purple." Mr. Norman confesses that 

 his powers of imagination are at fault, and that he fails 

 to see any connexion between Murex trunculus and " Mu- 

 reck-baan." The variety striata attains a much larger 

 size than the typical form ; I have a specimen nearly 

 an inch and a quarter long, an inch and a half broad, 



