28 CIRRIPEDIA. 



coincidences are accidental, and that the epizoons have no 

 special or sexual relation to the Cirripedes to which they 

 are attached ? 



One other instance of coincident structure is so im- 

 portant, that it must, even in this sketch, be noticed ; the 

 prehensile antenna) of the pupa are most important and 

 complicated organs, and differ in the different genera of 

 the same family; they are preserved in a functionless 

 condition throughout life, and in two instances I was able 

 accurately to compare these organs in the epizoon and in 

 the Cirri pede to which it was attached, and they were 

 identical in every particular. The full force of the excessive 

 improbability of this resemblance, and of the above coin- 

 cidences in structure, on the supposition of the epizoon 

 and its support not being sexually related, will hardly be 

 perceived without referring to the facts given in detail in 

 my former volume. 



Lastly, in the case of Cryptophialus (and indirectly in 

 that of Alcippe) the nature of the male epizoon is, I think, 

 actually demonstrated ; for I traced both it and the female 

 or ordinary form of Cryptophialus, through the same 

 several larval stages, from the egg, enclosed within the 

 sack of the female, to the pupa and mature animal. 

 Moreover, if the male nature and sexual relation to the 

 supporting Cirripede, be admitted in any one of these 

 epizoons, then so close is the agreement in habits, and to a 

 certain extent in structure, in all the foregoing epizoons, 

 that probably no one admitting one instance would dispute 

 the others, and further evidence would even be superfluous. 

 Indeed, had it not been for the following facts, I should 

 not have brought forward, either here in abstract, or in 

 other places in detail, so many arguments and so much 

 evidence. 



I have as yet not entered in detail on the sex of the 

 supporting Cirripede : in Cryptophialus, Alcippe, and in one 

 species of Ibla, I was able to demonstrate in many speci- 

 mens, that all the male organs, internal and external, were 

 entirely absent ; and consequently that these Cirripedes were 

 exclusively female. In Scalpellum ornatum, also, there is no 

 trace of external male organs (the state of the four dried spe- 



