16 HYALOSPHENIA. 



rower part downward, and including the mouth, which 

 appears as a clearer transversely oval, reniform or circu- 

 lar space ; composed of quartz-sand or chitinoid mem- 

 brane, colorless, yellowish or brown. Sarcode colorless. 



A very common species. When erect, the axis, pass- 

 ing from the centre of the mouth to the summit of the 

 shell is oblique, not perpendicular as in the preceding 

 species. The bottom of the shell is concave, and the 

 mouth is inflected and situated above the plane of the 

 border of the base. Size: spineless forms, from 90// 

 long by 78// broad to 232// long by 160// broad ; spine- 

 bearing forms from ISO// long by 120// broad, to 340/^ 

 long to 180^ broad. 



Hob. Ooze of ponds. 



Difflugia spiralis. SYN. : Difflugia, Leclerc ; D. spiralis, 

 Ehr., Bail., Fres., Pritchard, Carter, Wallich, Leidy ; Lecquereusia ju- 

 rassica, Schluniberger ; D. proteiformis, Wallich. 



Shell retort-shaped, body usually spheroidal, laterally 

 compressed, with a short, wide, cylindrical neck, obtuse 

 fundus and circular or oval terminal mouth. Within 

 the shell is a partition defining the neck from the body 

 and giving to the shell, by transmitted light, the appear- 

 ance of a single turn of a spiral. Size : length 96// to 

 188// ; breadth, 68// to 164^ ; thickness, 68/a to 136,. 



Hdb. Sphagnous and cedar swamps. 



GENUS VII. HYALOSPHENIA. 



SYN. : Hyalosphenia, Stein ; Difflugia, Tatem ; Catharia, Leidy. 



Shell compressed, ovoid to pyriform, composed of 

 transparent, chitinoid membrane ; mouth terminal, infer- 



