202 FRESH- WATER RHIZOPODS OF NORTH AMERICA. 



filling the shell or slightly contracted from its sides ; when shorter than the 

 cavity of the shell, mostly adherent to the fundus by a pair of pseudopodal 

 threads. Nucleus large, clear, and usually homogeneous. Contractile 

 vesicles occupying an intermediate zone of the sarcode. Pseudopods nu- 

 merous, forking, radiating in any direction from the mouth, but mostly on 

 a horizontal plane, susceptible of a great variety of movement and change 



of form. 



CYPHODERIA AMPULLA. 



Plate XXXIV, figs. 1-16. 



Diffiugia Ampulla, Ehrenberg: Bericht Prens. Ak. Wis. 1840, 199; Abh. Ak. Wis. 1871, Taf. iii, Fig. 11. 



? Difflngia Lagena. Ehrenberg: Abh. Ak. Wis. 1841, 413, Taf. iv, Fig. 11 ; 1871, Taf. ii, Fig. 2. 



Cyphoderia margaritacea. Sehlumberger: An. Sc. Nat. 1845, iii, 255. — Freseuius: Abh. Senck. Naturf. 

 Ges. 1856-58, ii, 225, Taf. xii, Fig. 28-36.— Stein : Sitzungsb. Bohm. Akad. 1857 (fide 

 Schulze). — Carter: An. Mag. Nat. Hist. 1864, xiii, 33, pi. ii, fig. 18. — Hertwig and Lesser: 

 Arch. roik. Anat. 1874, x, Sup. 132.— Leidy: Pr. Ac. Nat. Sc. 1874, 227 ; 1877, 294.— Schulzo : 

 Arch. mik. Anat. 1875, xi, 106, Taf. v, Fig. 12-20. 



Eughjpha currata. Perfcy: Kennt. kleinst. Lebensformen, 1852, 187, pi. viii, fig. 21. 



Lagynis baltica. Schultze : Organ. Poly tkalamien, 1854, 56, Taf. i, Fig. 7,8. 



Euglypha margaritacea. Wallich : An. Mag. Nat. Hist. 1864, xiii, 240,244,245, pi. xvi, fig. 48. 



Difflngia mnrgaritacea. Wallich: Ibidem, 245. 



Euglypha haltica. Wallich: Ibidem. 



Difflngia Seelandica. Ehrenberg : Abh. Ak. Wis. 1869, Taf. ii, Fig. 23. 



Ampullaria (Werneck). Ehrenberg: Ibidem, 1871, 234. 



Difflngia adunca. Ehrenberg: Ibidem, 1871, 248, Taf. iii, Fig. 8,9. 



? Difflngia alavamensis. Ehrenberg: Ibidem, Fig. 10. 



Difflngia nncinata. Ehrenberg: Ibidem, Fig. 13. 



Sologlypha, seu D. Assulina adunca, D. A. ulabamensis, D. A. Ampulla, D. A. margaritacea, D. A. unci- 

 nata. Ehrenberg : Abh. 1871, 246. 



Euglyj>hu,seu D. Assulina Seelandica. Ehrenberg: Abh. 1871, 243. 



Cyphoderia ampulla. Leidy: Pr. Ac. Nat. Sc. 1878, 173. 



Shell retort-shaped, with a short cylindrical neck curving downward, 

 and truncated by a circular mouth ; body of the shell oblong oval, with the 

 longitudinal axis, in the active or moving condition of the animal, more or 

 less inclined, but nearly horizontal ; fundus obtusely rounded, sometimes 

 flattened, frequently more or less prolonged or narrowed at the summit 

 into a nipple-like process. Color of the shell mostly yellowish, less fre- 

 quently colorless. 



Size. — Ranging from 0.112 mm. to 0.176 mm. long by 0.04 mm. to 

 0.08 mm. broad, with the mouth 0.01G mm. to 0.028 mm. wide. 



Locality. — The superficial ooze of springs, ponds, lakes, and ditches. 

 Pennsylvania, New Jersey, Rhode Island, Florida, Wyoming Territory, 

 and Nova Scotia. 



Cyphoderia ampulla has an oval oblong, retort-shaped shell, with a 

 short cylindroid neck curving downward to the mouth. See figs. 1-15, pi. 



