214 DESCRIPTION OF \JPolyf)astr\ca. 



neck, expansions branching, but slightly anastomotic. Size of shell 

 1 -26th to l-13th. Length of expansions one-half. 



Ghomia fluviatilis. — Globular, or ovoid, -without a neck ; expan- 

 sions palmate and anastomotic. Diameter 1 -290th to 1 -104th. 



G. hyalma, (Sehlumberger). — Lorica globular or rather ovoid, 

 smooth, soft, diaphanous, colourless ; foramen round, with a very 

 short neck, formed by a reflection of the lorica ; expansions filiform, 

 numerous, very fine, branching and anastomotic. Diameter l-865th 

 to 1 -520th. In rivulets. 



"Notwithstanding the absence of colour in the shell, (saysDujar- 

 din), I arrange this species in the genus Gromia. In size it also 

 differs from the other two species. The lorica being transparent, 

 admits to view, some blueish globules, and a large hyaline glandular 

 ovoid body, like that in the interior of other diaphanous RMzopodes." 



Genus MiLiOLA. — Lorica calcareous, ovoid, or depressed, having 

 but a single opening, consisting of several cells variously disposed. 

 Expansions filiform, radiating from the single orifice, which is bifid, 

 by the projection into it, on its inner side of a tongue-like process. 



The lorica is compact without pores, and either smooth, or vari- 

 ously marked by ribs or striae. Expansions very fine. 



Examples of this genus are very numerous in a fossil state with 

 other PolytJialamia, often constituting the chief components of large 

 masses of earth. Many of them are also visible to the naked eye. 



Genus Lecqtjeretjsia, (Sehlumberger). — Shell ovo-globular, or 

 retort-shaped, rather depressed, membranous, but resistant ; with a 

 wide short neck, and circular terminal aperture, giving passage to 

 cylindrical, tliick and obtuse expansions. 



This genus approaches Difflugia, (Duj.) in the character of its 

 expansions, but the very different form of the shell, and the position 

 of the aperture, sufficiently mark the distinction between the two. 



L. Jurassica. — Shell resistant, diaphanous, grey, of a globular 

 figure, but rather depressed with a short wide neck. Length about 

 1 -250th. Breadth 1-31 5th. 



This beautiful species is met with on aquatic, or other dead plants, 

 in many of the lakes of the Jura chain about Nefuchatel. Its 

 diaphanous lorica allows its interior soft hyaline and granular body, 

 strewn with brown specks, to be seen. 



