24 HELEOPERA. 



GENUS X. HELEOPERA. 



Shell compressed ovoid, composed of cancellated, chi- 

 tinoid membrane, presenting a reticulated appearance of 

 mostly dotted or interrupted lines, often incorporated with 

 particles of sand at the fundus. Mouth inferior, terminal, 

 large, transversely elliptical. Sarcode as in Hyalosphenia 

 and Nebela. Pseudopods numerous, digitifonn. 



picta. SYN. : Difflugia (Nebela) sphagni, Nebela 

 sphagni, Leidy. 



Shell compressed ovoid, never pyriform, with the oral 

 pole narrower ; mouth terminal, forming a long, narrow 

 ellipse with acute commissures, convex downward, acutely 

 notched on the narrow sides ; composed of a yellowish, 

 transparent, chitinoid membrane with a reticular structure, 

 meshes polygonal and lines of the net dotted. Sarcode 

 with bright-green endosarc, owing to numerous chloro- 

 phyll vesicles. Pseudopods digitate, simple and branched, 

 large and numerous, often writhing, snake-like. Length, 

 92/; to 168/z ; breadth, 76/i to 136// ; thickness, 44;/ to 72// ; 

 mouth, Wn by 16/z to 72// by 32^. 



Hob. Sphagnous swamps. 



Heleopera petricola. 



Shell compressed oval ; mouth terminal, broad, ellip- 

 tical, convex downward, with acute commissures in the 

 narrow view ; fundus convex, loaded with quartz grains ; 

 composed of chitinoid membrane, reticular, with poly- 

 gonal or rounded meshes, colorless or brownish. Length, 

 96/; to ISO;/; breadth, 68/ to 90/2, and 4&p to 60;*; 

 breadth of mouth, 52;* to 60;* by 15;/. 



Hah. Sphagnous swamps. 



