TESTACEA 389 



rounded ends in front view; elliptical in profile; ovoid with a small 

 central oval aperture in end view; 45-77)u by 23-45/i; in sphagnum. 



Genus Pseudodifflugia Schlumberger. Test ovoid, usually rigid, 

 with foreign bodies; circular or elliptical in cross-section; aperture 

 terminal; granulated cytoplasm colorless or greyish; nucleus poster- 

 ior; a contractile vacuole; filopodialong, straight or branching; fresh 

 water. Several species. 



P. gracilis S. (Fig. 181, j). Test yellowish or brownish; subspheri- 

 cal, with sand-grains; aperture without neck; 20-65/1 long. 



Genus Diaphoropodon Archer. Test ovoid, flexible, with minute 

 foreign bodies and a thick covering of hyaline hair-like projections; 

 pseudopodia long, filose, branching; fresh water. 



D. mobile A. (Fig. 181, k). Test brown; of various shapes; aperture 

 terminal; body does not fill the test; nucleus large; 1-2 contractile 

 vacuoles; 60-120/x long; projections 8-10ai long; in vegetation. 



Genus Clypeolina Penard. Test ovoid, compressed, formed of a 

 double envelope; outer envelope composed of 2 valves with scales 

 and particles; inner envelope a membranous sack; Icng filo podia, 

 often branching; fresh water. 



C. marginata P. (Fig. 181, I, m). Outer test-valves yellow to dark 

 brown; lenticular in cross-section; wide terminal aperture; endo- 

 plasm with many small globules; a single nucleus and contractile 

 vacuole; 80-150/x long. 



Family 4 Euglyphidae Wallich 



Genus Euglypha Dujardin ( Parevglypha Penard). Test hyaline, 

 ovoid, composed of circular, oval, or scutiform siliceous imbricated 

 scales, arranged in longitudinal rows; aperture bordered with regu- 

 larly arranged denticulate scales; usually with spines; 1-2 nuclei 

 large, placed centrally; filopodia dichotomously branched; contrac- 

 tile vacuoles; fresh water. Numerous species. 



E. acanthophora (Ehrenberg) (E. alveolata D.) (Fig. 70). Test 

 ovoid, or slightly elongate; 3-7 scales protruding around the circular 

 aperture; scales elliptical; body almost fills the test; 50-100/i long. 



E. cristata Leidy (Fig. 182, a). Test small, elongate with a long 

 neck, fundus with 3-8 spines; scales oval; aperture circular, bordered 

 by a single row of 5-6 denticulate scales; cytoplasm colorless; nucleus 

 posterior; reserve scales are said to be collected around the exterior 

 of aperture, unlike other species in which they are kept within the 

 cytoplasm; SO-lO/j. long; 12-23/i in diameter; aperture 6-12^; scales 

 4.5-9.5/i by 2.5-6. 5)u; spines 10-15/i long. 



E. mucronata L. (Fig. 182, h). Test large; fundus conical, with 



