EMBRYOLOGY OF BARNACLES. 275 



was at first thought to be an adult Crustacean, and described 

 under the name of Nauplius. The Nauplius 

 of the genuine barnacles (Fig. 227) has three 

 pairs of legs ending in long bristles, with a 

 single eye, and a pair of antennae, the body 

 ending in front in two horns, and posteriorly 

 in a long caudal spine. After swimming 

 about for a while, the Nauplius attaches it- 

 self to some object by its antennae, and now a 

 strange transformation results. The body is 

 enclosed by two sets of valves, appearing as if Alter Darwin, 

 bivalved, like a Cypris (Fig. 228) ; the peduncle grows out, 



Fig. S26. Comple- 

 mentary male of Seal' 

 pettum reffivm, greatly 

 enlarged. After Wy- 

 ville-Thompson. 



Fig Z25.ScalpeUui>ire<)ium. a, complementary 

 male, lodeeu within the valveg. After Wyville- 

 Thompson. 



