50 



Animal Life by the Sea-shore. 



i'lG. 57. CYPRIS LARVA OF SACCULINA, SIDE 



VIEW (after DELAGE). 



hard shell consisting of man}' pieces, some of which form valve- 



Hke plates which completely close its orifice. When the rock is 



washed by the 

 sea, these plates 

 gape apart and 

 expose six pairs 

 of fringed appen- 

 dages, by means 

 of which floating 

 organic particles 

 are captured and 

 used as food. 

 The goose- 

 barnacle [Lepas 



anatifera) is provided with long stalks which form bunches 



attached to floating timber and boats, and, after storms, 



these bunches are sometimes 



washed ashore (Fig. 55). Like 



most fixed animals, the major- 

 ity of Cirripedes are herma- 

 phrodite. The larval stages, as 



we have said, fix the position of 



these curious creatures in the 



classification. The young leaves 



the egg as a microscopic pear- 

 shaped creature with three pairs 



of appendages only ; such a larva 



is known as a Nauplius, and is 



characteristic of man}? divisions 



of the Crustaceans (Fig. 58). The 



Nauplius passes after a series of 



moults into a second lar^^al form, 



the Cypris (Fig. 57), which has 



the whole body enclosed in a 



large, loose carapace, with ej^es 



and feelers, as well as six pairs 



of biramous limbs. After a short 



free-swimming existence, the 



Cypris fixes itself, head down- ^,_ o 



wards, to some soHd object by oTsASuTiriowL^CrB;: 



means of its feelers; the eyes (after del age). 



disappear, and calcareous plates 



are developed in the carapace, thus forming the hard shell ol 



the adult. 



