Introduction to Animal 



59 



Fig. 4. 



Order 3. Hcliozoa (Fig. 4). Protoplasta with radiant pseu- 

 dopodia, often confounded with the last, but having a dif- 

 ferentiated endosarc containing nucleated masses, and a vacuo- 

 lated cctosarc, which appears alveolated. Each pseudopodium 

 is compound, having a firm endosarcal axis and a hyaline 

 granule-bearing ectosarcal surface-layer.* The endosarc has 

 no central capsule. They multiply by division, natural or 

 artificial, also (in Actinosphoerium) by encystation and the 

 division into many (10) resting spores, each in an Arcella- 

 like siliceous hexagonal test. 

 Raphidiophrys has fine siliceous 

 spicules traversing the large 

 green spherules, which make up 

 the body. Acanthocystis is 

 rounded with movable, straight, 

 bifid, hollow spines, discoidal 

 at the base, and curved flexible 

 spicules. f Actinosphxrium is 

 globular, like Actinophrys in 

 shape. Cystophrys has an irre- 

 gular body, and many spherical 

 endosarcal nucleated cells like 

 .'How cells of Radiolaria. 

 :<jphrys is globular, with 

 no spicules, and unbranched pseudopodia, but with central 

 cells. Diaphoropodon has a difflugia-like test of foreign 

 bodies. These are mostly freshwater forms, and many have 

 :,tly been discovered by Archer, Greef, and Focke. 



* In feeding, these do not surround the food, but draw it into the 

 ectosarc. 



t It is often the nidus of a Rotatorian. 



Hcliosphaera radiata Sch. 



