HYALOSPHENIA. 19 



elegans. SYN. : Di^gia (catharia) elegans, 

 Leidy. 



Shell compressed flask-shaped ; in broad side view, oval 

 body and long cylindroid neck, slightly widened at oral 

 end, which is convex downward ; narrow side long ellip- 

 tical, tapering to the oral end, which is deeply notched. 

 Shell of pale brownish, transparent, structureless, chitinoid 

 membrane, impressed with longitudinal rows of hemi- 

 spherical pits. Sarcode colorless, attached by threads to 

 the fundus of the shell ; pseudopods digitate, usually 

 three or four. This may be the same as Ehrenberg's 

 Difflugia spirigera. Common. Size : length, 88/1 to 

 108// ; breadth, 64/* to 40// ; thickness, 20// to 28//. 



Hob. Associated with H. papilio in sphagnum. 



GENUS. YIII. QUADRULA. 



SYN. : Difflugia, Wallich ; Assulina, Hologlypha, Ehr. ; Quadrula, 

 Schulze. 



Shell compressed pyriform, transparent, composed of 

 thin, square plates of chitinoid membrane, arranged in 

 transverse or more or less oblique series in consecutive 

 or alternating order. Mouth inferior, terminal, oval. 

 Sarcode colorless. 



Symmetrica. - SYN. : Difflugia proteiformis, pyri- 

 formis, symmetrica, Wallich ; D. Assulina assulata, D. Carolinensis, 

 leptolepis, Ehr. ; Quadrula symmetrica, Schulze. 



Shell compressed pyriform ; viewed on broad side 

 with fundus widely convex, and sides sloping or more or 

 less inflected toward the oral end, which is convex 

 downward ; narrower side ellipsoidal, fundus obtuse, 

 oval end roundly notched. Shell colorless, composed of 



