94 



THE CRUSTACEA 



increase in size, in some cases, to several times the length of the 

 body, and as the cuticle covering them is very thin it is believed 



ov- 



-3- s - 



Fio. 53. 



Stages in the life-history of Hufmocem ihinae. A, free-swimming nauplius-larva, x i>80. B, 

 embryo after penetrating into the body-cavity of the host; no organs remain except the 

 degenerating nauplius-eye. C, later stage, from the vascular system of the host ; the absorptive 

 processes have begun to develop. 1), still later .stage ; the absorptive processes are fully 

 formed and the posterior end of the embryo is provided with rows of recurved hooks. E, th 

 adult female, just before emergence from the host ; the anterior part of the body is distended 

 with eggs. F, free-swimming female, carrying the extruded eggs, x _'S ; the hypodermis in the 

 anterior part of the body has .separated from the cuticle after expulsion of the eggs and forms 

 a sheath around the nerve-cord, a', antennule ; for, brain ; e, nauplius-eye ; /, swimming-feet ; 

 g.s, genital setae ; m, position of mouth ; md, mandible of nauplius ; n, nerve-cord connecting 

 brain with ventral nerve-chain ; or, mass of eggs carried on genital setae ; cuv/, ovary ; pi; 

 absorptive processes. (After Malaquin.) 



that they act as absorptive organs. In some cases, but not always, 

 a second pair of these processes is found behind the first. From 

 the position which they occupy relatively to the rudiments of 



