SUN ANIMALCULES 



3535 



are composed of the shells of an allied genus {Nummulites) . As these rocks belong 

 to the Tertiary epoch, and form some of the highest Himalayan peaks, they indi- 

 cate how recently these mountains have been elevated. 



SUN ANIMALCULES Order HELIOZOA 



These animalcules are inhabitants of fresh water; their chief characteristic, and 

 the one to which they owe their name, being the possession of long, slender, some- 

 what stiff pseudopods, which radiate from all parts of the spherical body, like sun 

 rays, as represented in pictures. The common sun animalcule (Actinophrys) forms a 

 tiny translucent spherical globule, bristling with pseudopods, and about one-twa 

 hundred and fiftieth of an inch in diameter. The pseudopods appear stiff but 



GREEN SUN ANIMALCULE, Acanthocystis chcstophora (highly magnified). 



are quite flexible, and the body contains several clear vesicles, one of which is 

 usually half emerged from the body and on the point of bursting; the nucleus 

 being in the centre of the body. The animal can move over a hard surface by 

 the alternate relaxation and stiffening of its pseudopods, and sometimes so 

 quickly that it appears to run like a spider. When a pseudopod touches some 

 small organism, the latter seems to become paratyzed, the pseudopod approximat- 

 ing itself and its prey to the body, which sends up a lobe wherein the organism is 



