582 



DEPTHS OF THE OCEAN chap. 



took this genus in deep 



known from the Pacific.^ The " Michael Sars 

 water at several stations in the North Atlantic, 



The Cirripedia are the only group of crustaceans which in the adult 

 stage abandon the pelagic life of youth and become sessile, fixing them- 

 selves to the bottom like many other invertebrates. Some are fixed to 

 the rocks of the littoral region (the balani), or to pumice stones and 

 nodules from the great depths of the ocean, while others are attached to 

 whales and turtles, or (like the Lepadidae) to floating objects carried 

 along by currents. One species {Lepas fascicidaris) forms considerable 

 floating clusters composed of several individuals. A peculiar group 

 (for example, Sacculina from the tail of decapod Crustacea) is entirely 



parasitic and transformed to 

 such a degree that the crusta- 

 ceous nature of the animal is 

 hardly recognisable. 



The Cirripedia from the 

 Atlantic cruise of the " Michael 

 Sars " have been examined by 

 P. P. C. Hoek, who found the 

 following species of the genus 

 Lepas : — 



Lepas anatifera (see Chapter III., 

 p. loo, Fig. 87), taken at Station 

 61 (on a floating log), and off 

 St. John's. 



Lepas anserifera, Station 67 (on 

 Sargasso weed), Station 69 (on 

 a small log). 



Lepas pectinata^ Stations 10, 25, 31, 

 69, 86, 91 and 92 (fixed to birds' 

 feathers, cork, fucus, pumice- 

 stone, and to L. fascicularis). 



Lepas hii/i, Station 56 (on a turtle). 



Lepas fascicularis, Stations 25, 91, 92. 



All these species are known from other oceans, especially the Pacific, 

 and are principally warm-water forms. Of other Cirripedia the following 

 species were captured : — 



Fcvcilasma carinatmn, Station 53 (on the bottom). 

 Conchoderma virgatum, Station 56 (on a turtle). 

 Scalpelliim vehitinum, Stations 24 and 53 (on the bottom). 



„ dicheloplax, Station 10 (on the bottom). 



,, atlanticiim, Station 23 (on the bottom). 



G. O. Sars described 57 species of Schizopoda from the " Challenger " 

 Expedition,^ of which 32 were taken only at the surface, 6 between 32 

 and 3CX) fathoms, 4 between 300 and 1000 fathoms, 11 between 1000 

 and 2000 fathoms, and 4 beyond 2000 fathoms. Most of these were 



1 See G. W. Miiller, Wiss. Ergeb. " Valdivia" Expedition, Bd. 8, 1906. 

 2 See Zool. Chall. Exp., Part XXXVII., 1885. 



Fig. 419. 



Gigantocypris agassizii , G. W. Miiller (|) 



(From Miiller. ) 



