Sttnorhynchus Phalamgium. 

 Leptopddia sagittdta. 



As the shelly armour of the Crustaceans is, in most cases, so hard, strong, and 

 unyielding, the mode of growth might be considered a problem not very easy of solution. 

 For with the Crustaceans the growth continues during nearly the whole of life, or at all 

 events for several years after they have passed through the various changes to which they 

 are subjected in their imperfect stages of existence. Their increase of size and weight is 

 marvellously rapid, and how it can be accomplished without subjecting the Crustaceans 

 to the lot of the starveling mouse, who crawled into a jar of corn, but could not crawl 

 out again after feasting on its contents, seems to partake of the character of an animated 

 puzzle. 



The answer to the problem is simply that the creature sheds its armour annually, 

 expands rapidly while yet covered only by a soft skin, and is soon protected by a 

 freshly-deposited coat of shelly substance. Even this answer contains a second problem 

 little less difficult than that which it solves. How can a Crustacean, say a crab or a 

 lobster, shed its skin ? It is true that the cast shells are found, showing that the creature 

 has escaped from its old and contracted tenement by a slit in some part of the body, such 

 as the top of the carapace, and has left its shell in so perfect a state that it might easily 

 be mistaken for the living animal. 



But-how did it manage about the claws ? We all know what large muscular masses 

 they are, how very small is the aperture in which the joint works, and how stiff and firm is 

 the broad tendinous plate which is found in their interior. Examination shows that there is 

 no opening on the claws through which the creature might have drawn the imprisoned limb, 

 and it is also evident that the only method by which these members can be extricated, is 

 by pulling them fairly through the joints. As a preliminary step, the hard, firm, muscular 

 fibres which fill the claw and give it the well-known pinching power, become soft, flaccid; 



