26 



ZOOLOGY. 



ber, measures about one fifth of an inch in diameter. Most 

 of our native species are much more minute. The Eozoon, 

 so-called, is supposed by some to be a Foraminifer, but 

 others regard it as more probably inorganic, and simply a 



Fig. 15.—^, Collosphmra spi- 

 nosa, with j^rojecting conical 

 points, containing little Bphe- 

 roids, which pass into monad- 

 like bodies C. D, probably an 

 early stage of C. A, a young 

 capsule or C. Hnxleyi Miiller. — 

 Alter Cienkowski. 



Fig. \(j.—Actmospkmium. «, a mor- 

 sel of food di-awn into the cortical layer 

 b ; c, centra] parenchymatous mass of 

 the body ; cZ, some balls of food-etiiff in 

 the latter; e, pseudopodia of the cortical 

 layer.— After Gegenbaur. 



Fig. X7 .—Heliophrys variabUis. A sun- 

 animalcule, showing the pseudopods, 

 nuclei, and vacuoles. — From Macallister. 



mineral. Undoubted Foraminifera occur in the Silurian 

 formation, while large masses of carboniferous and cre- 

 taceous rocks are formed by their shells. 



Order 2. Radiolaria. — These Rhizopods have the general 

 structure of Amoebae, but secrete beautiful silicious shells, 



