124 ^S'/zd'// Lifi 



fringed. On some parts of our coast this mollusk 

 is known as the Mud Hen. It has a fondness for 

 stiff mud and clay beds at the mouth of rivers, a 

 little below low-water mark. It burrows to a depth 

 of about 6 inches, keeping open communciation 

 with the water above by means of its long tubes. 

 The Thin Furrow-shell {8. tennis) is a much smaller 

 and more triangular species than the last ; more con- 

 vex, thin, opaque, iridescent ; greyish white, often 

 stained by burrowing in clay. The animal is white, 

 with a delicate fringe to the mantle. The inhalent 

 tube is twice the length of the shell, the exhalent 

 tube one - third less. It appears to be fond of 

 brackish water, for it is found chiefly in mud at 

 low water along the estuaries of the south coast 

 from Kent to Devon. 



The Wedge - shells (Donax) are more triangular 

 than the Furrow-shells, the valves glossy though 

 partially scored by crossing grooves. The beaks 

 are a good deal behind the middle line. The valves 

 do not gape behind, and their inner margins are 

 usually " milled," so that the closed valves interlock. 

 There are two cardinals in the left valve, a double 

 central one in the right, and a lateral fore and aft in 

 each. The animal has a fringed mantle, short thick 

 diverging siphons, and a very large and pointed 

 sharp - edged foot. They are found in sand from 

 low-water mark to about 8 fathoms, but as they 

 burrow only an inch or so below the surface there 

 is no necessity for long siphons. The Banded Wedge- 

 shell (D. vittatus) is the best - known species. It 

 is variously coloured yellow, brown, olive, or purple, 

 often with three white rays from the beaks, and with 



