TESTACEA 339 



D. mobile A. (Fig. 154, k). Test brown; of various shapes; aper- 

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

 tractile vacuoles; 60-120)u long; projections 8-10/x long; in vege- 

 tation. 



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; long filopodia, 

 often branching; fresh water. 



C. marginata P. (Fig. 154, I, m). Outer test-valves yellow to 

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

 endoplasm with many small globules; a single nucleus and con- 

 tractile vacuole; 80-150ju long. 



Family 4 Euglyphidae Wallich 



Genus Euglypha Dujardin (Pareuglypha Penard). Test hya- 

 line, ovoid, composed of circular, oval, or scutiform siliceous im- 

 bricated scales, arranged in longitudinal rows; aperture bordered 

 with regularly arranged denticulate scales; usually with spines; 

 1-2 nuclei large, placed centrally; filopodia dichotomously 

 branched; contractile vacuoles; fresh w^ater. Numerous species. 



E. acanthophora (Ehrenberg) {E. alveolata D.) (Fig. 67). Test 

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

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

 long. 



E. cristata Leidy (Fig. 155, a). Test small, elongate with a long 

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

 dered by a single row of 5-6 denticulate scales; cytoplasm color- 

 less; nucleus posterior; reserve scales are said to be collected 

 around the exterior of aperture, unlike other species in which 

 they are kept wathin the cytoplasm; 30-70^ long; 12-23iu in 

 diameter; aperture 6-12;u; scales 4.5-9.5yu by 2.5-6.5//; spines 10- 

 15ju long. 



E. mucronata L. (Fig. 155, 6). Test large; fundus conical, with 

 1-2 terminal spines (12-44/i long); aperture circular, bordered by 

 a single row of 6-8 denticulate scales; 100-150/x long, diameter 

 30-60ju; aperture 15-20^ in diameter. 



Genus Paulinella Lauterborn. Test small ovoid, not com- 

 pressed; with siliceous scales in alternating transverse rows; aper- 

 ture terminal; body does not fill the test completely; nucleus pos- 

 terior; among vegetation in fresh or brackish water. 



