440 MACTRID^!. 



HABITAT : Estuaries, creeks, and bays, gregarious in 

 mud, from the low- water mark of spring tides to 40 

 fathoms. An odd valve was dredged by Capt. Beechey 

 off the Mull of Galloway in 110-140 fathoms. Var. 1. 

 Deal Voe, East Shetland, in 3 fathoms (J. G. J.). 

 Var. 2. Lough Strangford (Waller) ; Larne, co. Antrim 

 (J. G. J.). This species occurs in all our upper ter- 

 tiaries, from the Clyde basin to the Coralline Crag; 

 glacial beds at Uddevalla, and upper miocene strata at 

 Biot in the south of France ( J. G. J.) ; Panormi in Sicily 

 (Philippi). It is common on all the Scandinavian coasts 

 in 4-40 fathoms, and in other parts of the North-Euro- 

 pean seas from Boulogne to Lisbon in 7-30 fathoms, as 

 well as throughout the Mediterranean and JEgean in 

 3-50 fathoms. The variety radiata was found by Loven 

 in the Bohuslan district, by Malm at a depth of from 

 3 to 6 fathoms in the estuary of the river Gotha (where 

 the water is brackish), and by Meyer and Mobius in 

 Kiel Bay. A third and nearly transparent variety was 

 taken alive by Forbes at the great depth of 80-185 

 fathoms in the Gulf of Macri, and described by him in 

 the Reports of the British Association for 1843, under 

 the name of Ligula profundissima ; his typical speci- 

 mens are preserved in the British Museum. 



This little mollusk, although living in mud, takes care 

 not to be smothered in it, but keeps up its commu- 

 nication with the sea. If, in dredging it, the contents 

 of the net, mud and shells, are put into a tub and left 

 for some hours to settle, the S. alba will be seen on the 

 surface, having worked its way upwards by means of its 

 muscular and flexible foot. It reminds me of an anec- 

 dote connected with the British Association. During 

 the Southampton Meeting in 1847, Mr. M f Andrew 

 treated some of the members to a dredging-cruise in 



