EHIZOPODA 19 



FAMILY 3. EUGLYPHIDAE. 



Shell membranous and composed of plates of chitin or silica 

 enclosing a single chamber with a single large opening; pseudopodia 

 filiform and sometimes somewhat anastomosing; size minute: 5 genera; 

 mostly in fresh water. 



1. EUGLYPHA Dujardin. Shell elongate, ovate, often with spines 

 at hinder end and composed of oblique rows of round plates whose 

 edges overlap, making hexagonal areas; opening denticulate; pseudo- 

 podia fine, often branching but not reticulate: in fresh water; 4 

 species. 



E. alveolata Duj. (Fig. 13). Shell colorless, elongated 

 and cylindrical; hinder end broader, usually with a few 

 long spines ; plates composing it are round or oval ; length 

 .15 mm.: common. 



E. ciliata Leidy. Shell elongate and elliptical in 

 cross section; hinder end and sides with numerous short 

 spines; plates six-sided; length .1 mm.: common in 

 sphagnum moss. 



2. CYPHODERIA Schlumberger. Shell retort-shaped 



and composed of minute plates; opening turned to one Fig~l4 

 side; forward half of body contains numerous contractile Cyphoderia 

 vacuoles, and hinder half the nucleus; color yellowish: (Leidy). 

 2 species; in fresh and salt water. 



C. ampulla (Ehrenberg) (Fig. 14). Length .17 mm.: in ponds and 

 ditches. 



SUBORDER 2. RETICULARIIDA. 



Pseudopodia filiform and reticulate; calcareous shell usually pres- 

 ent which has either one or more large openings or many minute ones, 

 through which the pseudopodia project: 3 divisions. 



Key to the divisions of Eeticulariida : 



o x No shell present 1. NUDA 



o 2 Shell with one or more large and no minute openings 2. IMPEBFOBINA 



o s No large but numerous minute openings 3. PEKFOBINA 



DIVISION 1. NUDA. 



Rhizopods without shell and with reticulate pseudopodia: about 8 

 genera; mostly marine. 



BIOMYXA Leidy. Form incessantly changing; nucleus present or 

 apparently absent: 1 species. 



B. vagans Leidy. Color pale gray with oil globules, nucleus when 

 present large and distinct; no ectosarc: in sphagnum moss. 



