GREGARINIDA.—INFUSORIA. 7 
vision within the shell, the 
young at first resembling 
little oval bodies, with hair- 
like tails. 
VALUE.—The shells of the ma- . 
rine forms fall in a shower upon 
the bottom, and form chalk-beds, 
as the Dover cliffs, in England, 
thus adding to the land of the 
globe. The stone of the Pyramids : \ 
is made up of fossil Foraminifera. 
me: ay.— 
Sp aiid i or Stu y Fic, 4.—Flint-shelled Radiolarian 
The Amebe can be found (Heliosphera). 
on leaves in fresh-water 
ponds. foraminifera can be caught with a fine net in the 
ocean, or found in pools at low tide. The shells can be 
ground and mounted for the microscope. 
Class II].—GREGARINIDA. 
General Characteristics.—These (Fig. 5) are minute 
forms that take up their abode in lobsters, crabs, beetles, 
cockroaches, worms, and other animals, 
and lead a parasitic life, existing upon 
the juices of the animals they inhabit. 
They resemble minute worms; one, 
found in the European lobster, half an 
inch in length, is called Gregarina gi- 
gantea, being the largest single-celled 
Fic. 5.—Gregarinaof’ animal known. They undergo several 
Nemertes Gesseri- x : 
ensis, showingnu- CUTious changes before reaching mature 
cleusand granules, growth. 
Class [V.—INFUSORIA. 
General Characteristics—Animals of permanent form 
with cilia, or hair-like organs, for locomotion and procur- 
ing food. They are either free or stalked. 
