10 



ZOOLOGY. 



called Foraminifera (Laim, foramen, a hole or aperture; 

 ferens, bearing). 



In some forms, as tlic fossil Numnnilifes, the chambers 

 are numerons and I'egular, the shells being flat and consist- 

 ing of eight coils situated in the same plane. A recent 

 species of Foraminifer found at Borneo measures more 

 than two inches in diameter, wliile a common form on the 

 Florida reefs which is swallowed in large quantities by the 

 Holothuria, or sea-cucumber, measures about one fifth of 



Fig. 6.—Rotalia. A Ehizopod, showing the pseudopodia. 



an inch in diameter. Most of our native species are much 

 more minute. The Eozo'oh, so-called, is supposed by some 

 to be a Foraminifer, but others I'cgard it as of mineral ori- 

 gin. These Foraminifera float in calm weather on the sur- 

 face of the sea, and when tliey die their shells slowly sink 

 to the bottom. They are exceedingly abundant, and the 

 shells at the bottom accumulate in such quantities as to 

 make a gray mud or ooze forming the bottom of the ocean 

 at great depths: this soft, deep mud is called Uhjiigcriiui 



