SECT. n. RETICULARIA. 25 



preceding Ehizopods. The ectosarc or surface-layer 

 of the sarcode in the Aniceba and Actinophrys has so 

 much consistence, that their pseudopodia, which are 

 derived from it, have a decidedly firm outline and never 

 coalesce ; whereas in the order Reticularia, the sarcode 

 is merely a semi-fluid protoplasm or colourless viscid 

 fluid, without the smallest surface-layer or film, so that 

 their pseudopodia possess no definiteness either in shape, 

 size or number. Sometimes they are cylindrical, and 

 sometimes form broad flat bands, whilst they are often 

 drawn into threads of such extreme tenuity, as to 

 require a high magnifying power to discern them. 

 They coalesce and fuse into each other so freely and so 

 completely when they meet, that no part of their 

 substance can be regarded as having more than a 

 viscous consistence. Their margins are not defined by 

 continuous lines, but are broken by granules irregularly 

 disposed among them, so that they appear as if torn ; 

 and these granules, when the animal is in a state of 

 activity, are in constant motion, passing along the 

 pseudopodia from one end to the other, or passing 

 through the connecting threads of this animated net- 

 work from one pseudopodium to another, with con- 

 siderable rapidity, analogous to the movement of the 

 particles in the cells of the hairs of the Tradescantia 

 and other plants. 7 



The sarcode body of the Gromise is inclosed in a 

 yellowish brown horny envelope or test of an oval shape, 

 with a single round orifice of moderate size, through 

 which the pseudopodia extend into the surrounding 

 water, some forms of the animal being marine, others 

 inhabitants of fresh water. When the animal is at rest 

 all is drawn within the test, and when its activity 

 recommences, single fine threads are put out which 

 move about in a groping manner until they find some 



T Introduction to the Study of the Foraminifera,' by W. B. Carpenter. 



