HYALOSPHENIA. 17 



ior, transversely elliptical. Sarcode occupying the inte- 

 rior of the shell to a variable extent, attached to the in- 

 ner surface by threads and also to the border of the 

 mouth. Nucleus large and central ; contractile vesicles 

 several ; pseudopods digitate, few. 



Synopsis of the Genera of Hyalosphenia. 



Shell compressed ovoid, very delicate, colorless ; sar- PA OK. 



code colorless, Cuneata, 17 



Shell compressed ovoid, in narrow view oral end 



notched ; sarcode green, Papilzo, 18 



Shell compressed pyriform, pale yellow, with pair of 



pores on border, short neck ; sarcode colorless, Tincta, 18 

 Shell compressed flask-shaped, long cylindroid neck ; 



oral end in narrow view deeply notched, color 



brownish, longitudinal rows of pits, Elegans, 19 



Hyalosphenia CUneata, SYN. : H. cuneata, Stein ; Difflugia 

 ligata, Tatem ; Catharia ligata, Leidy ; Hyalosphenia lata, Schulze ; H, 

 ligatn, Leidy. 



Shell compressed ovoid, in narrow view conical and 

 truncate at the oral end, laterally and at the fundus con- 

 vex ; mouth terminal, oval ; in broader view fundus con- 

 vex with tapering borders, plane, convex or concave in 

 their descent to the mouth. Shell composed of delicate, 

 colorless membrane. Sarcode colorless, pyriform ; pseu- 

 dopods digitate, usually only one or two. The shell is so 

 delicate that the tension of the threads of ectosarc is suf- 

 ficient to bend it. Rare. Size : length 60^ to T6// ; 

 breadth, 44[t to 60^; thickness, 20//; mouth 16/a by 

 12;/. 



Hob. In ponds. 



