58 LEPADIDiE. 



resembled, in general appearance and size, the ovigerms 

 with their germinal vesicles and spots, which I have often 

 seen at the first commencement of the formation of the 

 ova in the ovarian tubes in the peduncle, that I cannot 

 doubt that such is their nature. Hence I conclude, 

 that these two gut-formed masses are the true ovaria. 

 I may add, that several times I have seen in the two 

 long, unbranched ducts, connecting the true ovaria and the 

 ovarian tubes in the peduncle, pellets of orange-coloured 

 cellular matter (*. e., ovigerms) forming at short intervals 

 little enlargements in the ducts, and apparently travelling 

 into the peduncle. 



The structure here described is quite comformable with 

 that which we have seen in the larva ; in the latter, two 

 gut-formed masses of equal thickness extended from the 

 caeca of the stomach to within the future peduncle, where 

 the cement-ducts entered them, and where, after a short 

 period, they were seen to expand into a mass of ovarian 

 tubes. In the mature Cirripede, the cement-ducts can 

 still be found united to the ovarian tubes in the middle of 

 peduncle ; and the cause of the wide separation of the true 

 ovaria and ovarian tubes, can be simply accounted for by 

 the internal, almost complete intersection of the animal, 

 which takes place during the last metamorphosis. 



The ova, when excluded, remain in the sack of the 

 animal until the larvae are hatched ; they are very nume- 

 rous, and generally form two concave, nearly circular, 

 leaves, which I have called after Steenstrup and other 

 authors, the ovigerous lamella (PL IV, fig. 2 b). These 

 lamellae lie low down on each side of the sack : in Concho- 

 derma virgata, however, there is often only a single lamella, 

 forming a deeply concave cup : in C. aurita there are gene- 

 rally on each side four lamellae, one under the other. The 

 ova lie in a layer from two to four deep ; and all are held 

 together by a most delicate transparent membrane, which 

 separately enfolds each ovum : this membrane is often 

 thicker and stronger round the margins of the lamellae, 

 where they are united, in a peculiar manner, presently to be 



