CRABS. 39 



are very grave reasons, however, why this opinion 

 should be received with the greatest caution, if not 

 absolute doubt. In the first place, we know of no 

 crustacean possessing a like power of silicious secretion 

 and construction. Then the Crabs which are found 

 inclosed are not always of the same species, or even 

 genera. Dr. Gray is of opinion that one which he 

 examined tlirough the meshes was a PaguruSj and of 

 habits identical with those which we haA^e already 

 described. Crabs with such investigating and intru- 

 sive instincts as these, would not fail to explore the 

 inmost recessess of a hollow tube of such a tempting 

 appearance as the young, growing, and coverless Eii- 

 plectella would present; and what more probable 

 than that, as the tube became perfected and the lid 

 partly made, the Crab or Crabs might still continue 

 to inhabit it, until the orifice being at last closed up, 

 and escape imjDossible, our friend remained a prisoner 

 for life. His cast-off shells, like old worn-out garments, 

 would remain sealed up securely with him, and give 

 the idea that many Crabs had there resided. 



The ancients, although totally ignorant of the 

 existence of the beautiful lace-work basket we have 

 described, and the creatm^es dwelling within them, were 

 nevertheless perfectly aware of the presence of small 

 Crabs in the shells of the great silk-yielduig mussel 

 {Pinna nohilis), who, because he had no visual organs 



