90 FEESH-WATER EHIZOPODS OF NOETH AMEEICA. 



former position, and a series of four cells, still connected together, from the 

 latter position. The animal then became globular and quiet, and measured 

 0.2 mm. in diameter. 



On the same occasion, in the same drop of water, I observed another 

 fine Dinamceba, with an oval body 0.25 mm. long by 0.2 mm. broad, with 

 numerous subulate pseudopods projected in all directions. It exhibited a 

 thickly papillose tail-like appendage 12 mm. long by 0.06 mm. broad. 

 The tail was filled with fine granular matter, a multitude of darkly defined 

 oil-like molecules, clear globules, and three cells of Didymoprium. The 

 animal afterward discharged a group of cells of the latter alga from the 

 body to the left of the tail, and subsequently assumed a long clavate shape 

 0.4 mm. long by 0.18 mm. broad at the thicker end. 



In one instance I observed a Dinamceba, which contained, with other 

 food, a desmid, the Closterium didymotocum, as represented in fig. 1, pi. VII. 

 When first seen, the alga held a transverse position causing a considerable 

 protrusion of the body on the left side. The alga had evidently been 

 seized. just after it had parted from another; — ^for one-half of the cell was 

 comparatively tender and doubled upon the older and more rigid half. 

 With the Closterium, smaller algae, and other ordinary materials, there was 

 an unusually large vacuole, which discharged itself several hours after first 

 observing it. About eight hours after seeing the Dinamceba, the minute 

 spicules of the surface had disappeared, and two hours later the Closterium 

 was discharged, but without my having seen the act. The following morn- 

 ing the animal presented the appearance represented in fig. 2. It was 0.21 

 mm. long by 0.12 mm. broad at the fore part. The pseudopods were remark- 

 ably long, up to 0.12 mm., and projected in every direction. The posterior 

 extremity ended in a number of compound papillae. The endosarc, besides 

 colored food-balls, contained a multitude of colorless globules. Three 

 smaller ones of these appeared within the tail end as contractile vesicles. 

 No trace of the minute spicules, usual in Dinamceba, was to be seen on 

 any part of the surface of the animal. 



In the Proceedings of the Academy of Natural Sciences for 1874, 

 page 167, I described an amoeboid, under the name of Amoeba tentaculata, 

 as follows: Body spheroidal, oval, or limaciform, projecting a multitude of 

 long conical or fusiform pseudopods of clear ectosarc,. into which no gran- 



