58 BRITISH FRESHWATER, RH1ZOPODA. 



anteriorly, and the animal moves forward in an almost 

 direct line, having a wide frontal margin of clear 

 ectoplasm. The nucleus and contractile vesicle are in 

 the posterior region, the latter usually in advance, 

 and the endoplasm contains, besides food-particles, a 

 variable number of minute crystalline bodies. 



Dimensions : Length 50-60 ^ ; average breadth 

 about 15 /LI. 



In ponds, etc., with Amoeba guttula, and generally 

 as plentiful. 



This species is more active than Amoeba guttula. Its 

 mode of progression approaches that of some forms of 

 A. proteus and A. villosa, but it is more uniform, and 

 Penard points out its peculiar habit of changing the 

 direction of its march by a movement of the anterior 

 portion of the body en masse, to right or left, whilst 

 the posterior remains stationary. This habit is cer- 

 tainly rare amongst the Amoebae. 



9. Amoeba verrucosa Ehrenberg. 

 (Plate V, figs. 1-3.) 



Amoeba verrucosa EHRENBERG Infus. (1838), p. 126. t. viii, 

 f. xi; PRITCHARD Hist. Infus. (1842), p. 166; new ed. 

 (1852), p. 202; and ed. 4 (1861), p. 549 ; PERTY Kenntn. 

 kleinst. Lehensf. (1852), p. 188 ; SCHMARDA in Denkr. K. 

 Akad. Wiss. Wien, VII (1854), 2, pp. U, 25 ; CARTER in 

 Ann. Nat. Hist". (2) XX (1857), pp. 37, 40, t. i, S. 12, 13 ; 

 PICK in Ver. Vereins Wien, VII (1857), p. 36; CARPENTER 

 Foram. (1862, Ray Soc.), pp. 36, 39; t, iv, f . 8 ; RYMER 

 JONES Anim. Kingd. ed. 4 (1871), p. 20; FROMENTEL 

 Etudes Microz. (1874), p. 348, t. xxix, f. 7; LEIDY in 

 Proc. Acad. Nat. Sci. Phil. 1874, p. 167; op. cit. 1876, 

 p. 198; op. cit. 1878, p. 158; and Freshw. Rhiz. N. 

 Amer. (1879), p. 53, t. iii (excl. f. 37) ; MAGGI in Rend. 

 R, 1st. Lomb. (2) IX (1876), p. 441; CATTANEO in Boll. 

 Scient. I, an. 1 (1879), pp. 7, 27, 57; op. cit. Ill, an. 10 

 (1888), p. 93; and in Atti Soc. Ital. XXII (1880), 

 p. 254; PARONA in Boll. Scient. I, an. 2 (1880), pp. 46, 

 48, and an. 4 (1882), pp. 51, 56; HITCHCOCK Synops. 

 Freshw. Rhiz. (1881), p. 5; VEJDOVSKY Thier. Org. 



