328 THE FAUNA OF THE EXE ESTUARY. 



Tapes decussata (Linnccus). Living specimens were moderately 

 common lying on the surface of the gravel on the north side of the 

 Warren and east of the stream draining Greenland Lake (sta. 12). A 

 few on gravel on Bullhill Bank and on coarse ground on Cocklesand. 



Tellina balthica, Linnceus. Common on the mud-flats between 

 Cocklesand and the L. and S. W. Station; a few on mud south of 

 Lympstone mussel bed, and one or two on the west bank of the estuary 

 between the Warren and Powderham. Nearly all the specimens 

 obtained were lying on the surface of the mud, only one having been 

 obtained by digging. They appear to be very shy animals, as we never 

 saw one expanded, although they were kept alive for two or three 

 days before preserving. 



Tellina tenuis, Da Costa. This bivalve was very connnon on the 

 west side of Polesands at low- water mark ; moderately common on the 

 fine [sand between Cocklesand and Lympstone mussel beds, and a few 

 were also taken on Bullhill Bank, the Warren, and Shaggles Sand. 

 They were generally found buried two or three inches below the 

 surface of the sand. On Polesands, where they were most common, 

 three or four would be turned up in one spadeful of sand. 



Tellina tenuis was always found on sand and T. halthica on mud. 



Donax vittatus {Da Costa). This mollusc was very common on 

 the smooth banks of fine sand running off the west side of Polesands. 

 Almost every specimen had a tuft of fine green weed or Enteromorpha 

 (occasional) attached to the posterior (short) end of the shell. The 

 animal being buried only just below the surface with the posterior end 

 uppermost, the tuft of weed was always visible either waving in the 

 water or lying on the sand, thus marking the position of the shell. A 

 few of the living shells had hydroids growing on them, in addition to 

 the weed, tlie hydroid being in three cases Pcrigonimns repens. 



Mactra solida, Linnmus. Not uncommon on Polesands in the same 

 situation as Donax vittatus. When first uncovered by the tide they were 

 generally found buried just below the surface, but after a time they 

 emerged from the sand and lay uncovered until the tide rose again. 



Mactra stultokum, Linnmus. A few shells only of this bivalve 

 were found on Polesands. 



Lutraria elliptica, Lamarck. Shells only on Polesands. 



Scrobicularia piperata {Linnceus). One of the commonest bivalves 

 of the Exe estuary ; it was almost always present where the ground 

 was composed of fine stiff mud. It occurred in profusion on Green- 

 lands (sta. 1), on the mud inside Cocklesand (sta. 13), near Salthouse 

 Lake (sta. 11), and all along the west bank, where the ground was 

 suitable. It was generally found buried three to six inches below 



