PROTOZOA 17 
kiihnia (Fig. 12), an allied form, the pseudopodia anastomose 
to a great extent and form a close reticulum. 
Fic. 12.—Lieberkiihnia, with 
reticulate pseudopodia, 
CLass V. Heliozoa. 
Mostly spherical in form, sometimes supported by a siliceous 
skeleton, and with radiating stiff pseudopodia. The protoplasm 
of the body is very. vacuolated, and contains one or more nuclei. 
Near the surface of the body one or more contractile vacuoles 
may be observed. With few exceptions, they inhabit fresh 
water. 
Actinophrys sol, the sun animaleule (Fig. 13), is one of the 
common microscopic objects found in still fresh water. It may 
be met with floating amongst the leaves of submerged plants, 
and presents a globular body which undergoes slight changes of 
outline, and is usually very vacuolated. The single nucleus 
occupies a central position, the contractile vacuole is on the 
surface, and food vacuoles containing portions of algae, infusoria, 
etc., may be seen throughout the body. The pseudopodia are 
stiff and hair-like, and are supported by an axial fibre; they 
can be withdrawn into the body. When they come in con- 
tact with a particle of food they bend slowly over it, and bring 
it near to the surface of the protoplasmic body, when it is 
swallowed with the surrounding drop of water, and thus a food 
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