RADIOL ARIA 



257 



groove of the body, which makes them resemble certain Dino- 

 flagellida. Further development is unknown; it is, however, 

 supposed that the anisoswarmers are sexual and isoswarmers 

 are asexual generations. 



Fig. 102 The life-cycle of Actipylea. (After Kiihn, modified). 

 a, grown individual; b, c, binary fission; d, e, budding process; f, adult 

 individual similar to a; g, formation of swarmers; h-j, supposed, but not ob- 

 served, gametogony of two swarmers producing a zygote; k, 1, young individu- 

 als. 



Enormous number of species of the Radiolaria are now 

 known. An outline of the classification is given below, together 

 with a few examples of the genera. 



