ANNULOSA : CRUSTACEA. 



195 



the abdomen, and never bears any appendages. For this 

 reason, many authorities do not regard it as a somite, properly 

 speaking, but simply as an azygos appendage that is to say, 

 as an appendage without a fellow. In the next segment (the 

 last but one, or the last, of the abdomen, according to the view 



Fig. 59. Morphology of Lobster, i. Lobster with all the appendages, except the 

 terminal swimmerets, removed, and the abdominal somites separated from one 

 another, ca Carapace ; t Telson. 2. The third abdominal somite separated, t Ter- 

 gum ; s Sternum ; / Pleuron ; a Protopodite ; b Exopodite ; c Endopodite. 3. One 

 of the last pair of foot-jaws or maxillipedes. e Epipodite ; g Gill ; the other letters 

 as before. 



which is taken of the " telson "), there is a pair of natatory ap- 

 pendages, called "swimmerets." Each swimmeret (fig. 59, 2) 

 consists of a basal joint, which articulates with the sternum, 



