582 ORDER ABDOMINALIA. 



a wrist-joint. The antennae, when retracted within the 

 carapace, lie parallel to each other. 



Posteriorly to the antenna?, I distinctly saw the apodemes 

 to which the eyes are attached : I was not able to distin- 

 guish any middle fork to the apodeme, which consequently 

 does not resemble a UU, but U. The eyes are dark pur- 

 ple, and, as usual, compound : in one specimen I counted 

 twelve ocelli within the common spherical envelope. 



I could not distinguish any thorax, and certainly there is 

 no mouth ; nor, from analogy, could the latter be expected, 

 excepting as forming part of the young cirripede : there are 

 no natatory legs, which the pupae in all other cirripedes 

 possess. Of the three postero-ventral pairs of bristles, the 

 most posterior or dorsal pair, differs from the other two 

 pairs in being considerably smaller, and in being mounted 

 on elongated pedicels : the two anterior pairs of bristles are 

 strong: the three pairs are articulated, one behind the other, 

 on a small body, apparently enclosed in a minute sack, and 

 certainly attached all round by membrane to the internal 

 edges of the orifice, through which the bristles are protruded. 

 These bristles, when the pupa was alive, were often moved, and 

 served apparently to steady the body during the alternate 

 protraction and retraction of the prehensile antennae. From 

 the fact of the pupa of other cirripedes having an abdomen, 

 formed of three segments, placed exactly in the same posi- 

 tion as the minute body here supporting the three pairs 

 of spines, I believe this body to be the abdomen. In other 

 cirripedes only the posterior segment of the abdomen bears 

 spines, which are supported on little limbs or pedicels, 

 namely, the caudal appendages, the other segments being 

 naked. But as the mature Cryptophialus, unlike other 

 cirripedes, has abdominal cirri, the presence of spines on the 

 corresponding abdominal segments in the pupa, is explained 

 and rendered probable : there can, I think, be little doubt 

 that the small terminal pair of spines, supported on elon- 

 gated pedicels or limbs, answers to the caudal appendages 

 found in many cirripedes. 



The whole course of the metamorphosis is very peculiar. 

 The gradual changes in the egg-like larva? (for I suppose 

 they must be called larva?) from a simple oval egg, to pointed 



