GENUS NEBELA— NEBELA ANSATA. 159 



species of Nebela. Usually it presents the ordinary form, but sometimes 

 individuals are observed in which processes of it extend into the lateral 

 horns. These processes are, however, not persistent, and the animal may 

 retract them entirely into the sarcodic mass, as it does the pseudopods, or 

 the threads of attachment to the fundus of the shell. 



Nebela ansata is a large species, and its shell measures from r } 5 th of an 

 inch to Mb. of an inch in length, j~th inch to ^th inch in breadth at the 

 points of the lateral horns, and ^th inch to ^ 8 th inch in breadth at the fun- 

 dus, with the thickness ^th inch. The mouth averages about 5 -^th of an 

 inch by -^th of an inch. 



I have found Nebela ansata in the moist sphagnum of the cedar swamp 

 of Absecom every year since my first notice of it in J 874. It is about as 

 frequent as Nebela carinata, with which it is found in association, as well as 

 with the other species described. 



In September, 1874, I observed a specimen in which the mouth of the 

 shell was closed by a doubly convex epiphragm, the sarcode was contracted 

 into a mass nearly filling the body of the shell above the position of the 

 lateral horns, and the interval was nearly filled with yellowish dirt, appa- 

 rently the food remains discharged from the sarcode mass. The following 

 morning the sarcode had extended itself so as to compress the dirt within a 

 smaller space against the epiphragm. The third day the specimen was 

 found, as seen in fig. 4, with the sarcode contracted into a compressed 

 spheroidal ball, and with the dirt occupying a still smaller space than pre- 

 viously within the neck of the shell. 



NEBELA BARBATA. 



Plate XXIV, figs. 14-17. 



Difflugia (Nebela) barbata. Leidy : Proe. Ac. Nat. Sc. 1874, 157. 

 Nebela barbata. Leidy : Proc. Ac. Nat. Sc. 1876, 119, fig. 18. 



Shell bottle-form, slightly compressed, with the neck cylindroid, and 

 about as long as the ovoidal body ; fundus obtuse, oral end slightly expand- 

 ed, and in the longer diameter convex downward ; mouth oval, entire. 

 Shell transparent, colorless, composed of circular disks, and furnished with 

 short stiff cilia. 



Size. — Length 0.08 mm. to 0.12 mm.; breadth of body 0.044 mm. to 



