LEPADID.E. 527 



only have alluded to its existence, had it not been for the 

 genus Alcippe, which differs in so many important cha- 

 racters from the other members of the Lepaclidae, that for- 

 merly I did not even suspect that it could belong to this 

 Family, and therefore deferred its examination. The genus 

 Alcippe was discovered, well described and illustrated, in 

 1849, by Mr. Hancock; to whose very great kindness I am 

 indebted for permission to dissect and examine his entire 

 stock of this truly remarkable Cirripede. In the classifi- 

 cation of the whole class I have not felt so much doubt, as 

 whether I ought to institute a family for the reception of 

 this genus. Alcippe differs from all other Cirripedes 

 (putting on one side for the instant, the males and com- 

 plemental males of Ibla and Scalpellum) in the very sin- 

 gular fact of being destitute of a rectum and anus ; — 

 in the three segments of the thorax, which usually support 

 the second, third, and fourth pairs of cirri, being without any 

 appendages ; — in the fifth and sixth pairs of cirri having their 

 inner or posterior rami metamorphosed into very singular 

 roughened cushions or buttons, which apparently serve to 

 triturate the food ; — in the caudal appendages being mus- 

 cular, and being used conjointly with the cirri ; — and lastly, 

 in the pupa having a lesser number of segments in its ab- 

 domen and caudal appendages than in (as far as I have seen) 

 any other Cirripede. It will be thought that these cha- 

 racters are amply sufficient to justify the placing Alcippe 

 in a separate family, more especially when the close general 

 resemblance in the animal's body in most of the other mem- 

 bers of the Balanidae, Verrucidae, and Lepadidae, is borne in 

 mind. On the other hand, the males and complemental males 

 of Scalpellum and Ibla must indisputably be considered as 

 members of the Lepadidae ; yet the male of ScatyeUum vul- 

 gar e and ornatum has no stomach, anus, or mouth, which is a 

 far more abnormal structure than the absence only of the 

 anus in Alcippe : the cirri, also, in these same males, differ 

 from the ordinary cirripedial type decidedly more than in 

 Alcippe. Again, in the male of Ibla, all the cirri, excepting 

 the fifth and sixth pairs, are aborted, and these two pairs 

 are usually only uniramous ; here, then, we have a decided 

 resemblance to Alcippe. Hence, if we might assume that 



