74 CO^CHYL\X—DITHYIiA. 23. 



Mactra glauca. Gmelin, Syst. p. 3260. 



Ttirton, Linn. Syst. iv. p. 212. 

 Montagu, Test. Brit. p. 571. 

 Donovan, British Sliells, iv. tab. 125. 

 Pennant, Brit. Zool. iv. p. 192. 

 hinn. Trans, viii. p. 68. 

 Turton, British Fauna, p. 155. 

 Dillwyn, Descript. Catal. p. 144. 

 Ttirton, Concli. Diet. p. 80. 

 Mactra helva. Chemnitz, vi. p. 234, tab. 2 J, fig. 232, 233. 



Found by Miss Pocock on Hale sands, in Cornwall; from which 

 neighbourhood some single valves have been lately procured 

 by General Bingham. 



Shell nearly two inches and a half long, and three and a half 

 broad, of a pale color marked with faint irregular glaucous rays, 

 fiattish and finely striate transversely : the beaks recurved, not 

 quite central, with a narrow gape under them. 



frsRilis. Mactra testa ovato-ohlonga planiusculd subtequilaterali Usvi, 

 antice anguloso Jlexuosd. 

 Shell oval-oblong tlattish nearly equilateral and smooth, with an 

 angular flexure at the anterior side. 



Tab. nost. 4, fig. 10. 

 Mactra fragilis. Gmelin, Syst. p. 3261. 



Turton, Linn. Syst. iv. p. 213. 

 Chemnitz, vi, p. 236, tab. 24, fig. 235. 

 Mus. nost. Dredged in the Channel, near Guernsea. 



