FORAMINIFERA. 



The Foraminifera, though constituting the most extensive and im- 

 portant-order of the Rhizopods, are almost exclusively marine. A single 

 well-known genus, Gromia, is represented by several species, inhabiting 

 salt and fresh water. 



GROMIA. 



? Greek, prumaia, a small bag. 



Animal spherical or oval, composed of granular protoplasm, with a 

 large central nucleus, and invested with a homogeneous chitinoid mem- 

 brane. Mouth situated at one pole of the body, and more or less copiously 

 emitting streams of protoplasm, which flow around the body and extend 

 into numerous pseudopodal rays, freely branching and anastomosing, so as 

 to form an intricate net, which exhibits an incessant flow of granules along 

 the filaments, both outward and inward. 



GROMIA TERRICOLA. 



Plate XLVII, figs. 1-4. 

 Gromia terricola. Leidy : Proc. Ac. Nat. Sc. Phila. 1874, 88. 



Body spherical or oval, pale yellowish or cream-colored, and more or 

 less translucent. Investing membrane or shell chitinoid, homogeneous, thin, 

 transparent, colorless, or pale yellowish, smooth, or with more or less adhe- 

 rent sand and dirt. Interior protoplasm white by reflected, pale yellow by 

 transmitted light, composed of a pale granular basis with fine oil molecules, 

 usually a few clear vacuoles of variable size, and a large, clear or pale 

 granular nucleus. Mouth obscure, emitting an abundance of finely granu- 

 lar protoplasm, which ordinarily flows around the body, and then breaks 

 up into a multitude of diverging streams or filamentous pseudopodal rays, 

 that frequently form and anastomose so as to produce an intricate net. An 

 incessant circulation of granules outward and inward along the course of 

 the pseudopodal filaments. 



Size. — From 0.112 mm. to 0.12 mm. in diameter; the oval variety 

 0.112 mm. long by 0.1 mm. broad. 



