26 J'HYSIQLOGY OF THE INVERTEBRATA. 



division of the shell are protruded. In the Imperforata "the 

 food for the whole colony is seized and taken in by the 

 pseudopodia given off by the individual segment found in the 

 last-formed, and therefore most free cavity of the shell." 



Nearly all the Foraminifera are marine animals ; whereas 

 the AmcebcB chiefly inhabit fresh water, although some are 

 found in the sea. 



(d) The Catallacta. — There is a morphological difference- 

 between this order and the Frotoplasta, g,lthough the mechan- 

 isms of their digestive functions are closely allied. 



Magosphcera (Fig. 2, c) which represents the Catallacta, 

 protrudes pseudopodia which are broad at the base, while 

 the other extremities break up into a number of very fine 

 filaments. We may term these secondary pseudopodia. 

 Magosphcera has a well-marked contractile vacuole. 



(e) The Badiolarict. — One of the most common of this 

 order is Adinophrys (the sun-animalcule). It has stiffish 

 pseudopodia, " which radiate from all sides of the globular 

 body." Adinophrys (Fig. 2, d) has a contractile vacuole, but 

 secretes no shell. In Adinosphcerium (Fig. 2, e) the " central 

 part of the protoplasm is distingushed from the rest by con- 

 taining a number of endoplasts" (nuclei). Most of the 

 Radiolaria are simple and solitary organisms, but Sphmrozoum 

 and CoUosphcera form colonies. 



In the case of Adinophrys sol any part of the body serves 

 as a way of entry for food ; in fact it is a pantostomate being 

 (W. S. Kent). 



(/) Infusoria. — Under this head Professor Huxley 

 includes — 



Infusoria flagellata (the " Monads "), 

 Infusoria tentaculifera (the Acinetce). 

 Infusoria ciliata. 

 The Infusoria are the well-known inhabitants of water 

 containing decomposing vegetable matter. These organisms 

 differ entirely from those previously described, inasmuch as 

 they have a permanent aperture — the mouth. Beyond this 



