CIREIPED TRANSFORMATIONS. 283 



The number of these little intruders varies from one 

 upwards. I possess specimens, one of which carries 

 nine, the other eleven; the appearance of the ovate 

 barnacles, each with its conspicuous orifice, crowded 

 all round the edge of the coral, is exceedingly curious 

 and novel. Mr. Holdsworth mentions, however, that 

 he has seen fourteen Pyrgomata attached to a single 

 Cctryophyllia, which was dredged in Plymouth Sound. 1 



The transformations of these animals, as investigated 

 by Mr. Darwin, are of great interest. The Cirripede, 

 whatever its genus, and whatever its peculiarities of 

 adult existence, begins its life in a form exactly like 

 that of a young Entomostracous Crustacean, with a 

 broad carapace, a single eye, two pairs of antennae, three 

 pairs of jointed, branched, and well-bristled legs, and a 

 forked tail. It casts off its skin twice, undergoing, 

 especially at the second moult, a considerable change 

 of figure. At the third moult it has assumed almost 

 the form of a Gypris, or Cytliere, being enclosed in a 

 bivalve shell, in which the front of the head with the 

 antennas is greatly developed, equalling in bulk all the 

 rest of the body. The single eye has become two, which 

 are very large, and attached to the outer arms of two 

 bent processes like the letters u u, which are seen with- 

 in the thorax. 



i Zoologist, pp. 7054, 7111- 



