9'> 



Guide to Crustacea. 



Wall- 

 cases 

 Nos. 1-3. 



Fig. G. 



Series of cast shells obtained from a single 

 individual of the Shore-Crab (Carcinus 

 inaenas) kept in an aquarium. The 

 carapace of the largest is about 2^ inches 

 wide. [Wall-Case No. 3.] 



of the Edible Crab, of which 

 one is in the act of moulting. 

 The carapace has become 

 separated . from the abdomen 

 and legs, and the body is 

 beginning to be withdrawn 

 from it. 



On the right of the case is 

 a series of cast shells obtained 

 from a single individual of the 

 Shore-Crab (Fig. 6). The crab 

 was captured on 14th May, 

 1901. It was then in the 

 second larval or Megalopa 

 stage, and was found swimming 

 at the surface of the sea. It 

 lived in Mr. Waddington's 

 aquarium till 20th July, 1904, 

 and during that period it 

 moulted seventeen times. All 

 the cast shells, except two which 

 were destroyed by accident, are 

 exhibited. 



In the lower part of the 

 case two very beautiful series 

 are exhibited, each obtained 

 from a single Lobster in Mr. 

 Waddington's aquaria, and to- 

 gether they give an almost 

 complete picture of the growth 

 of the animal from an early 

 post-larval stage until it reaches 

 a marketable size. The younger 

 series begins with a specimen 

 of about ;^ths inch length of 

 body, which moulted on 21st 

 August, 190G ; the latest of the 

 fourteen moults exhibited was 

 obtained on 8th June, 1909, 

 when the animal was about 

 4^ inches in length. The second 

 series begins with a specimen 



