94 



CRUSTACEA — CIRRIPEDIA 



very much in the state characteristic of the Cyj^ris larvae of other 

 Cirripedes, being furnished with two terminal hooks by which 

 attachment is effected. The thoracic appendages, of which there 

 are the normal number six, are reduced flabellate structures, and 

 the abdomen forms an indefinitely segmented lolie of consider- 

 able size. 



The animal appears to be in an arrested state of dcAelopment, 

 and so retains some of the characteristics of the Cypris larvae, but 

 it is very doubtful how far these characters can be considered 

 primitive. 



Other forms are Bendrogastcr astericola on Echinoderms, 

 and Synagoga mira on the " ISlack Coral," Faranti^Kithes larix, at 

 Naples. 



Sub-Order 5. Apoda. 



Darwin described a small liermaphrodite parasite in the; mantle 



chamber of Ale'pas cor- 

 nuta from Saint \m- 

 cent, "West Indies, 

 which he named Pro- 

 teoleiJas hirincta. 



Tlie body (Fig. 

 65) is distinctly seg- 

 mented into eleven 

 somites, the last three 

 of which are supposed 

 to belong to the ab- 

 domen ; there are no 

 appendages except the 



-Proteolepas hivincta, x 26. J, Antennae ; antennae by which 

 a, b, 1st and 2nd aljdominal segments ; 0. OYary ; fixation is effected. 

 P, penis ; 7", telson ; 1-8, thoracic segments. (After rri-i , , „ , i , „ 



DaAvin.) i he mouth-parts are of 



normal constitution. 

 This animal has not been found again since Darwin's dis- 

 covery, but Hansen^ describes a number of peculiar Nauplius 

 larvae taken in the plankton of various regions, which he 

 argues probably belong to members of this group. A wide field 

 of work is offered in attempting to find tlie adults into which 

 various larvae grow. 



' Plankton Expedition, ii. G. d. 1899. 



