GENUS PELOMYXA— PELOMYXA VILLOSA. 73 



commonly more or less leech like or sing-like in shape, and differentiated 

 into an anterior and a posterior region, habitually with the broader 

 extremity in advance, and progressing through the projection of a wave- 

 like or hemispherical expansion of clear ectosarc, in front or successively 

 upon either side, or from other parts of the body ; posteriorly frequently 

 ending in a conspicuous process of clear sarcode, which is prehensile, and 

 often finely villous. Body composed of a clear ectosarc with a finely 

 granular endosarc containing variable proportions of clear vacuoles and 

 other more consistent colorless globules. Nuclei numerous, scattered 

 through the endosarc. Contractile vesicles small and inconspicuous, except 

 in the young. Animal voracious and usually more or less gorged with 

 vegetal and animal materials, together with considerable mud and sand. 



PELOMYXA VILLOSA. 



Plate V, with the name Amoeba villosa; VIII, figs. 31-33. 

 Amaba sabulosa. Leidy : Proc. Acad. Nat. Sc. 1874, 87. 



Animal nearly opaque, except when young, appearing, by transmitted 

 light, brown or black with hyaline border; by reflected light, yellowish 

 white and maculated with other colors dependent on the contained food; 

 spheroidal or ovoidal and somewhat depressed in the resting condition; 

 habitually clavate or botuliform when in motion; straight, curved, or 

 sigmoid; moving with the thicker extremity in advance; with a terminal 

 circular villous patch, which may be projected into a mammillary or ball- 

 like process; villi numerous, minute, papillary or filiform, simple or ramose. 

 Pseudopods usually as one or two broad lobar projections of the fore part 

 of the body, preceded by a thick seam of clear ectosarc, rarely prolonged or 

 branching, sometimes accompanied with a few narrow conical processes of 

 clear ectosarc projecting from any part of the body. Nuclei many, 

 scattered through the endosarc. Contractile vesicles many, small and 

 inconspicuous, usually occupying a position in the vicinity of the villous 

 area. Animal exceedingly gluttonous, usually gorged with algous and 

 other food, dirt, and sand, which more or less obscure from view the 

 intrinsic elements of structure ; motion sluggish, flowing, and more or less 

 intermittent; villous extremity prehensile, often seen clinging to fixed 

 objects or dragging after it adherent dirt or food materials. 



Size. — In the ordinary resting or spheroidal condition from 0.12 to 

 1.25 mm., but commonly from 0.25 to 0.5 mm. In the elongated or clavate 



