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supposes it very likely that he may be asked, how he knows that these 

 rudimentary epizoons are really the males of the Cirripedes to which 

 they attach themselves, and answers " that even if the whole course of the 

 metamorphoses had not been known in three of the cases, the mere fact of 

 these epizoons being cemented by the three terminal segments of their 

 peculiar, pupal antennas, would have been sufficient to have shown that 

 they belonged to the class of Cirripedes." He was also able to demonstrate, 

 in nearly every case, that these epizoons were males ; and as in several 

 cases the spermatozoa were developed, and in no instance, notwithstanding, 

 was there a vestige of ova or ovaria, it may safely be concluded that they 

 were not hermaphrodites, and, therefore, required females of some kind. 

 And who would, under these circumstances, conclude that they had no 

 special or sexual relation to the female Cirripedes to which they are 

 attached ? This subject is most fully treated of in the text ; but we give 

 the above interesting, though curious facts, hoping it may be the means of 

 making some of our readers take an interest in this strange class of 

 creatures. In speaking of the metamorphoses of the Cirripedes, Mr. 

 Darwin says as follows : 



u I have reason to believe that the metamorphoses undergone can be reduced into 

 three principal stages or heads, and that these three include all the main changes. 

 First, larvae in first stage Their shape is oval and the whole dorsal surface is evi- 

 dently covered by a carapace ; the body exhibits no distinct articulations ; the eye 

 varies considerably in the state of its development, and is of different shapes. In 

 Scalpellum vulgare we see arising posteriorly to the eye a pair of minute curved 

 horns directed backwards. These horns are very difficult to make out, and proba- 

 bly could not be seen previous to first moult in any larva of smaller size than that 

 of S. vulgare ; but after the first moult these appear to enclose the first pair of an- 

 tennae ; the second pair are not found until the pupal state. The mouth is more or 

 less probosci formed, differing considerably in this respect in different species of 

 the Lepadidse; during its very early stages there are no jaws; but the labrum is 

 furnished with some short, thick, sharp spines and some hairs. We come now to 

 the three pairs of natatory legs ; the first has throughout the order only one ramus, 

 whereas the two succeeding pairs are biramous. After the first moult these limbs 

 are furnished with plumose spines, some curved and some straight and strong, which 

 are most probably prehensile. Lastly, behind the natatory legs on the ventral sur- 

 face, the body is much produced and terminates in a horny fork, which, after the 

 first moult, becomes much elongated ; after the first moult the posterior end of the 

 carapace becomes much elongated and serrated on both sides. Situated under this 

 posterior prolongation of the carapace there is a swelling which apparently lies on 

 the dorsal surface of the spinose and forked abdomen ; here, ^hen the larva is com- 

 pressed, the cellular and oily contents of the body burst forth ; and I suspect that this 

 swelling is the anus. Larva second stage Only one specimen has hitherto been 

 observed of a larva in this stage. The carapace has now greatly altered its character. 

 The small internal and anterior pairs of antennae are, it would now appear, aborted ; 

 the eye has commenced becoming double ; the mouth is probosciformed and does 

 not differ much from its condition in the first stage ; the first pair of legs is unira- 

 mous, and the two other pairs biramous ; the abdomen has become much shortened, 

 but still space is left for the development in the pupn of the three posterior pairs of 

 legs. Larva in the third or pupal stage On comparison with the larva in the 

 second stage, the changes in external appearance and structure are not very great ; 



