269 



area, on the sides of which project 

 the single pair of incubatory plates, 

 and behind the latter the long 

 occluding folds of the incubatory 

 cavities. 



9Ventr. ar. Anterior part of ventral face, 

 more highly magnified. On left 

 side the legs and eoxal plates are 

 removed, in order to show more 

 distinctty the underlying left incu- 

 batory plate. 



mp. Maxilliped. 



Strn. Sternal plate. 



9-P E - Leg of 5th pair. 



9juv. Very young female, with attached 

 larval male; dorsal and ventral 

 views. 



cf ad. Adult male, dorsal view. 



cfad*. Same, viewed from left side. 



cf C. Same, cephalon and 1st pedigerous 



segment from below. 



cf Urs. Same, extremity of tail, with the 

 rudimentary uropoda. 



cflarv. Young male in last, larval stage; 

 doisal view. 



cf larv.C. Same, cephalon and 1st pedigerous 

 segment from below (right inferior 

 antenna and left 1st leg omitted). 



cf larv.p 6 . Same, leg of 6th pair. 



cflarv.p 7 . Same, leg of 7th pair. 



cflarv.TJrs. Same, extremity of tail, dorsal 

 view. 



PI. 97. 

 Cydroniseus cydridinae, G. 0. Sars. 



Central fig. A female specimen of Oypridina 

 norvegica infested with this parasite, 

 viewed from right side, the right 

 valve being removed. Besides the 

 fully grown female, occupying the 

 incubatory cavity of the host, 

 another very young female is seen 

 attached laterally to the skin of 

 the Cypridina. 



'Jad. Adxilt; ovigerous female, dorsal and 



ventral views, magnified to the same 

 scale as the preceding figure. 



tub. an. Same, anal tubercles, highly mag- 

 nified. 



9 1 . Femal larva, immediately after it 



has attached itself to the host; 

 dorsal view. 



$ 2 . Another recently attached female 



larva, which is about to shead its 

 skin. Within the latter the cha- 

 racteristic fusiform body of the next 

 stage is distinctly traced. 



9 3 . Young female in the 1st postlarval 



stage, ventral view. 



9 3 *. Another female in same stage, 



viewed from right side. In both 

 specimens the neck is still covered 

 by some of the anterior empty 

 larval segments, with their append- 

 ages in a more or less complete 



state, whereas the head with its 

 root-like filaments is deeply buried 

 into the skin of the host. 



$juv. Anterior extremity of body in about 

 this stage, viewed from below (only 

 the bases of the root-like filaments 

 drawn). 



$ 4 . Somewhat more advanced stage, 



dorsal view. 



$ 5 . Immature female, after the neck 



has been converted to the affixing 

 string ; viewed from right side. 



9 6 . A somewhat more advanced female 



with attached male, viewed from 

 right side. 



PI. 98. 



1. Cyproniseus eypndinae (contin.) 



cf . Adult male, dorsal view. 



C. Same, anterior part of body from 



below (left inferior antenna and the 

 2 anterior legs on same side not 

 drawn). 



cox. A coxal plate. 



p 3 . Leg of 3rd pair. 



p r . Leg of 7th pair. 



pip. Pleopod. 



Urs. Extremity of tail, dorsal view. 



2. Cryptothir balani (Sp. Bate). 



9. Female (not fully grown), dorsal 



view. 



C. Anterior larval part of body, ven- 



tral view. 



3. Aseoniseus simplex, G. 0. Sars. 



9ad. Adult female with attached larval 

 skin, viewed from left side. 



9juv. Young female, likewise with attached 

 larval skin, viewed from right side. 



cf . Adult male, dorsal view. 



cf C. Same, cephalon and 1st pedigerous 



segment from below (left inferior 

 antennae and right 1st leg not 

 drawn). 



cf p 3 . Same, leg of 3rd pair. 



cf p 7 . Same, leg of 7th pair. 



cf Urs. Same, extremity of tail dorsal view. 



PI. 99. 

 1. Clypeoniseus Hanseni, Giard & Bonn. 



9- Adult female, dorsal and ventral 



views, 

 an. t. Caudal process (anal tubercle) of 



same, highly magnified, 

 cf . Male, dorsal view. - 



cf C. Same, anterior part of body from 



below (left inferior antenna and 



right 1st and 2nd legs not drawn). 



