PLATE II. 



Figs. 1-13.— AMCEBA PEOTEUS. 



Fig. 1. Individual iu a condition repeatedly observed immediately Bucceeding those represented 

 in figs. 1, 2, of tlie preceding plate. Body ovoid with long divergent pseudopods. n, nucleus ; p. v., con- 

 tractile vesicle. 200 diameters. Ditch below Philadelphia. 



Fig. 2. Au individual of stellate' form, as frequently observed when swimming. The largo con- 

 tractile vesicle central, with the nucleus in advance to the left. Same locality. 



Fig. 3. Small individual, similar to that of fig. 8 of the preceding plate and found with it. p. v., 

 contractile vesicle; «, nucleus. A large diatom extends across the posterior part of the body. 500 

 diameters. 



Fig. 4. An active individual with a profusion of pseudopods, containing a large granular nucleus, 

 together with vacuoles, brown food-balls, diatoms, minute crystals, etc. 250 diameters. In several 

 similar individuals the nucleus ranged from 0.032 mm. to 0.036 mm. broad by 0.02 mm. thick, and the 

 contractile vesicle enlarged to 0.036. With Bladder-wort, Jacksonville, Florida, February, 1875. 



Fig. 5. Individual from China Lake, Mount Gilbert, Uinta Mountains, Wyoming Territory, 

 August, 1877. The yellow septate alga seen in the figure was afterwards observed to be expelled. 200 

 diameters. 



Fig. 6. Robust individual, containing two contractile vesicles and a discoid nucleus. Among the 

 food contents of brown balls, grains of sawdust, etc., there may also be noticed an Arcella. 270 diam- 

 eters. Absecom pond. New Jersey. 



Another individual accompanying the former, at one time extended in a cylinder, with a single 

 divergent psendopod, and measured 1.2 mm. in length. 



Fig. 7. A large and unusually pale, translucent, and seemingly starved individual, containing 

 only colorless food-balls, together with clear vacuoles and contractile vesicles. Ko nucleus detected. 

 200 diameters. Sphagnous bog-water, Pokono Mountain, Monroe County, Pennsylvania, August, 1876. 



Fig. 8. Small individual, found in company with that of fig. 3.- 2.'>0 diameters. 



Fig. 9. Appearance of the nucleus in a large individual like those of figs. 1, 2, from the same 

 locality. 350 diameters. 



Fig. 10. Appearance of the nucleus of another and similar individual after the action of acetic 

 acid. 250 diameters. 



Fig. 11. Extremity of a chief pseudopodal extension, intending to represent the mode of entrance 

 of the granular endosaro into the advancing ectosarc. In the former many clear vacuoles and numerous 

 crystals are seen. 500 diameters. 



Fig. 12. Apparent forms of crystals as seemingly observed in tile same individual from Which the 

 preceding figure was drawn. 2,500 diameters. 



Fig. 13. Api>arent forms of other crystals observed. 1,00Q diameters. 



Figs. 14-16. Probably young of AMCEBA VILLOSA. £00 diameters. From water squeezed from 

 wot moss from the crevices of pavements in Philadelphia. 



Fig. 14. Individual containing a discoid nucleus, and as food several diatoms and a fragment of 

 Lyngbya. 



Figs. 15, 16. Two views of the same individual, ending in a posterior minutely villous ball. 



