GENUS PELOMYXA— PELOMYXA VILLOSA. 77 



condition or spheroidal form of the animal it is not obvious, and it appears 

 to be capable of complete retraction and obliteration, as is the case with 

 the ordinary pseudopodal extensions. It is variable in appearance, though 

 as ordinarily seen it forms a discoid or sucker-like process defined from the 

 rest of the body by a constriction. When not projected, it is sometimes 

 visible as a circular patch terminating the posterior extremity of the body, 

 as represented in figs. 1, 13. Sometimes the process appears as a conical 

 or irregularly papillary projection. The villi are very variable; sometimes 

 numerous, minute and crowded; sometimes fewer, thicker and Avidely 

 separated; at times short and papillary, at others more or less long and hair- 

 like, and occasionally branched. See figs. 1-10, 12, 13, 15-17. 



The villous portion or process of the body is highly prehensile, and 

 serves the animal to fix its position in like manner with the sucker of a 

 leech. At times when I have poured off the liquid from the glass on which 

 I was examining a specimen of the Pelomyxa to put on it clearer water, it 

 would maintain its place by means of the villous end of the body. As a 

 temporary organ of prehension it is no doubt of importance in obtaining 

 food. Algae and other materials are often seen adherent to and dragged 

 along after it in the progressive movements of the animal, as represented 

 in fig 14. In structure, the villous process appears as an extension of finely 

 granular homogeneous endosarc without the slightest differentiation of 

 enclosing ectosarc, and when it is of irregular or papillary form it looks as 

 if it were a sort of hernial protrusion of the endosarc through an accidental 

 rupture of the ectosarc. 



Sometimes the villous area of Pelomyxa villosa appears only as a villous 

 fringe to the posterior extremity of the body. Occasionally I have observed 

 an individual emit a multitude of minute villi near or in conjunction with 

 the usual villous area, or in other positions of the body. These addi- 

 tional or supjdemental villi appeared to be less permanent than the others, 

 or at least after a time they were withdrawn and were no longer visible in 

 the same individual. 



Pelomyxa villosa I have usually found to be so opaque, except in young 

 specimens, that the different elements of its interior structure are undis- 

 tinguishable without the animal is submitted to considerable pressure, or it 

 is actually crushed. In habit, like the Pelomyxa palustns, it is exceedingly 

 gluttonous, and is remarkable for the manner in which it gorges itself with 



