DESCRIPTION OF GENERA AND SPECIES. 
Family I. GROMID-ZE. 
The Gromid^e, as generally defined, are Reticularian Rliizopods, with an imperforate 
chitinous investment. The investment is either in the condition of a thin pellicle or skin 
adhering closely to the body of the animal, or, more commonly, forms a distinct test, which 
the animal may or may not completely fill. The investment or test is normally homo- 
geneous, and is either hyaline, yellowish, or of light brown colour. In rare instances the 
exterior is encrusted with sand-grains or other foreign matter. The general aperture, 
when single, is central and axial, or nearly so ; when there are two mouths they occupy 
the opposite poles of the test. 
The classification of the naked and chitinous Rhizopoda into Lobosci, Filosa, and 
Reticularia, according to the characters of their extended pseudopodia, is convenient, and 
perhaps the best that can be devised with our present limited knowledge ; but the 
relationship of some of the Filose types to the Reticularian is so close as to suggest that 
the distinction is only one of degree. 
In the Synopsis of this family only the distinctly Reticularian genera have been 
retained ; that is to say, those in which the pseudopodia take the form of long, delicate, 
much-branched sarcode filaments, with ragged and irregular edges, inosculating in places, 
and very mobile — the transparent matter being loaded with granules which are carried 
along in more or less evident currents. 
The number of genera of chitinous Rhizopods that can be included amongst the 
Gromidjs with this restriction is at present only five. Of these, Lieberlcuehnia has a 
flexible investment adhering closely to the body of the animal, and constantly changing 
form. Gromia and Mikrogromia have ovate chitinous tests, differing from each other 
in little except size — true tests, of which the cavity is not always filled with sarcode. In 
the genus Diaphoropoclon the chitinous investment is strengthened by the incorporation of 
foreign bodies ; and, in addition to the long reticulated pseudopodia issuing from the 
general aperture, there are numberless delicate, filose extensions, short, hyaline, and of 
nearly equal length, springing from amongst the extraneous bodies encrusting the 
surface of the test. These four genera are characterised by a single aperture ; there 
