168 BRITISH BIRDS. 



were compared by Dr. Forsyth Major and Dr. Scharff with 

 bones of the several species of Grouse, and they were 

 found to agree better in some respects with those of Red 

 Grouse than with those of Ptarmigan. Some bones from 

 Kish Cave, co. Shgo, have been referred by Mr. E. T. 

 Newton to Red Grouse (?) or Ptarmigan (?). The former is 

 common in Ireland while the latter is unknown. 



R. J. USSHER. 



THE OYSTER-CATCHER'S METHOD OF FEEDING ON 

 THE EDIBLE MUSSEL. 



The systematic methods adopted by Oyster-catchers in 

 abstracting mussels from their shells are admirably detailed 

 by Mr. J. M. Dewar in the " Zoologist " for June. 



It is somewhat surprising to find that no shells larger than 

 If inches by | inch were found opened, while shells less than 1 

 inch by ^ inch were swallowed whole. 



The larger shells are dealt with in a most methodical manner. 

 No attempt is made to attack them when their valves are 

 closed : hence, those left high and dry by the tide, or in rain- 

 water pools, are always passed over unmolested. The shell 

 must be more or less gaping to arrest attention. As everyone 

 knows who is famihar with mussel-scalps, these molluscs 

 assume varied positions, sometimes presenting the ventral, 

 sometimes the dorsal border, uppermost, and sometimes one 

 end of the shell. And of these positions, shells with the dorsal 

 borders uppermost are most sought for, no less than 78 per 

 cent, of the empty shells left by Oyster-catchers having 

 occupied this position at the time of attack. 



Each mussel is approached in the hne of its long axis, and 

 generally, for some inexplicable reason, this approach is made 

 " from the front." Should the shell be shghtly gaping a 

 tentative tap is given, as if to ascertain whether the sht is 

 large enough for the beak to enter. If the experiment is 

 favourable, the beak is thrust home by a series of jerks, 

 forcible and rapid. When the blow is dehvered a little to 

 one side, so as to force inwards a portion of one side of a 

 valve, more deliberation is displayed, which suggests that the 

 abstraction of the animal from its case is a matter of certainty, 

 the body being dragged out through the hole made, in spite 

 of the closing of the valves. 



The author describes, in great detail, a number of methods 

 in the use of the beak as a lever, after it has once been thrust 

 down between the valves. These we cannot repeat, but it 

 should suffice to say that the simplest method employed is 



