48 A HISTORY OF RECENT CRUSTACEA 



of which has from of old been fancifully called ' the lady 

 in the chair.' The character of all the internal organs of 



FIG. 1. A lobster's stomach opened to show the teeth, the central one of which has 

 been supplied with eyes, nose, and mouth, to represent 'the lady in the 

 chair.' [Herbst] 



a crustacean, as exemplified in the crayfish, has been 

 already discussed in detail by Professor Huxley in a pre- 

 vious volume of this series. It may here, therefore, suffice 

 to recall that in a crustacean the heart is dorsal, the nerve- 

 chain, with the exception of the brain, ventral, and the 

 alimentary canal central, having in proximity the hepatic 

 lobes or liver, and the testes and ovaries. Some of the 

 more or less striking peculiarities which prevail in different 

 groups in regard to these organs are reserved for mention 

 as occasion offers in the description of the several sub- 

 orders and their families. 



The following table supplies a synopsis of all the 

 leading groups of the Crustacea. The literal meaning 

 of the various names has been explained in the first 

 chapter : 



