46 THE ZOOLOGIST. 



by the process of hammering. There is, thus, a considerable 

 loss of feeding material. This loss is the third disadvantage of 

 the method. 



Still smaller shells — that is, those ranging from five-eighths 

 of an inch to half an inch in length (f in. to \ in.) — are- treated 

 in a cavalier fashion commensurate to their feebler powers of 

 resistance.* They may be entered by a single, even, downward 

 thrust of the bill between the valves and then levered open, or 

 they may be hammered open with or without subsequent lever- 

 age. These shells are much crushed. Sometimes they are 

 seized crosswise within the tips of the mandibles, and either 

 jerked from their anchorage, or pulled off with an apparently 

 gentle to and fro motion of the bill, or levered up by raising the 

 tip of the bill and depressing the head, a neighbouring shell 

 being used as a fulcrum. These easy ways differ markedly from 

 that accorded to the larger shells, which need powerful tugging 

 to detach them from the rocks. Then, the shells which have 

 been removed so easily are set down on a bare place and ham- 

 mered open. If wide separation of the valves is necessary, the 

 requisite leverage is very often combined with scooping-up of 

 the contents ; and the acme of the process is reached when a 

 bird enters a small shell either by thrusting or hammering, 

 jerks it off the rock, scoops up the contents in mid-air, and casts 

 away the empty shell by a vigorous shake of the head, leaving 

 the soft body of the Mussel within the tips of the mandibles. 

 This proceeding takes place so quickly that it is inconceivable 

 the bill can have been introduced into the shell otherwise than 

 slightly open, and in one instance, at least, I believe the relative 

 positions of the mandibles never changed from the beginning to 

 the end of the operation, though at no time was it possible, as 

 viewed at the range of observation, to say that the mandibles 

 were even separated. 



Modioli modiolus. 



The Oystercatcher searches for immature individuals of the 

 Horse Mussel near low water and in the pools between tide- 

 marks. Very often the shells are scattered rather than crowded 



Cf. ibid., p. 210, where a method of opening these shells is first de- 

 scribed. 



