94 CRUSTACEA—CIRRIPEDIA CHAP. 
very much in the state characteristic of the Cypris 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 lobe of consider- 
able size. 
The animal appears to be in an arrested state of development, 
and so retains some of the characteristics of the Cypris larvae, but 
it is very doubtful how far these characters can be considered 
prinitive. 
Other forms are Dendrogaster astericola on Echinoderms, 
and Synagoga mira on the “ Black Coral,’ Parantipathes lari, at 
Naples. 
Sub-Order 5. Apoda. 
Darwin described a small hermaphrodite parasite in the mantle 
chamberof Alepas cor- 
i nuta from Saint Vin- 
cent, West Indies, 
which he named Pro- 
teolepas bivincta. 
The 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 
Fic. 65.—Proteolepas bivincta, x 26. A, Antennae ; antennae by, ee 
a, 6, Ist and 2nd abdominal segments; 0. ovary ; fixation is effected. 
ney T, telson ; 1-8, thoracic segments. (After The 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 the adults into which 
various larvae grow. 
1 Plankton Expedition, ii. G. d. 1899. 
