218 FRESH-WATER RHIZOPODS OF NORTH AMERICA. 



plasm, and sometimes portions of discharged food are seen between the 

 sarcode mass and the epiphragm. The sarcode then becomes contracted 

 into an oval or spheroidal ball occupying the central portion of the shell. 

 Under a change of circumstances, as a renewal of moisture and warmth, 

 the sarcode may be stimulated to activity, when by pressure the epiphragm 

 will be discharged from the shell, and the animal resumes its usual move- 

 ments. Otherwise, the contracted ball of sarcode becomes invested with 

 a membranous wall, and thus assumes the encysted condition. Under 

 what circumstances the ovum-like form, with a shell composed of plates 

 like those of the parent shell, is produced or developed, I did not learn. 



Euglypha ciliata is commonly about 0.083 mm. in length by 0.055 mm. 

 in its greater breadth, and one half this in its less breadth. Ordinarily 

 it ranges from 0.055 mm. in length by 0.016 mm. in the greater breadth, 

 to 1 mm. in length by 0.06 mm. in the greater breadth. The variety 

 EuglypJia strigosa I have observed ranging from 0.08 mm. in length by 

 0.06 mm. in greater and 0.032 mm. in less breadth, to 0.112 mm. in 

 length by 0.08 mm. in greater and 0.04 mm. in less breadth. 



Euglyplia ciliata was first most clearly described by Mr. Carter under 

 the name of Euglyplia compressa, and subsequently under the same name 

 by Dr. Schulze. Originally, however, it appears to have been indicated 

 by Ehrenberg under the name of Dijjlugia ciliata. 



Fig. 19, pi. XXXV, represents a somewhat peculiar specimen of Eugly- 

 pha, in which the shell was oblong oval, and of uniform transverse diame- 

 ters, as in E. alveolata, but furnished with hairs over a greater part of the 

 surface, as in E. strigosa. The plates of the shell appeared distinctly 



hexagonal. 



EUGLYPHA CRISTATA. 



Plate XXXVII, figs. 1-4. 

 Euglypha vristata. Leidy : Pr. Ac. Nat. Sc. Phila. 1874,226; 1878, 172. 



Shell tubular, flask-shaped, moderately inflated toward the fundus 

 and tapering gradually to the mouth which is slightly contracted, circular 

 in transverse section, hyaline, colorless, composed of oval plates in alter- 

 nating longitudinal series, overlapping at the borders, and appearing as 

 hexahedral areas limited by zones of minute elliptical areolae, sometimes 

 appearing to be composed of distinct hexagonal plates closely adapted 

 by the edges. Mouth round, bordered by 4-6 angular, serrulated teeth. 

 Fundus of the shell furnished with a central tuft of curved radiant spines. 



