tup: amp]ri(;an monthly 



[January, 



tlie jelly-mass. The expanded body 

 extends beyond this mass, when 

 fully contracted it is drawn down 

 into it. The extended body of the 

 species under consideration is elong- 

 ated, tapers gradually from its point 

 of greatest diameter, which is in the 

 - 



inferior third of the body, to a 

 small, rounded, inferior extremity. 

 Above the dilated portion, the 

 diameter, after diminishing for a 

 short distance, becomes uniform 

 almost up to the mouth, where it 

 expands slightly. Peristome an- 



. 1^ 



EXPLANATION OF THE FIGURES. 



Fig. I. The animal attached and ex- 

 tended, a, Endoplast. b, Contractile 

 vesicle, c. Chlorophyll granules, most 

 apparent in the dilated portion of the 

 body, d, " Fusiform body." <?, CEso- 

 phagus. /, Anus, g-. Disc, A, Peris- 

 tome with cilia (</), /, Transverse 

 striae. ^, Point of attachment to stalk 

 (/.). w. Division of stalk. ?/, Stalk re- 

 maining after detachment of animal. 



Fig. 2. Animal partially contracted ; 

 peristome and disc inverted ; the letters 

 refer to the same parts as in Fig. i (except 

 which refers to the inverted extremity.) 



Fig. 3. Animal more contracted, and 

 attached. Lettered as above, with addi- 

 tion of p the posterior circlet of cilia. 



Fig. 4. One of the free individuals, very* 

 recently detached. 



Fig. 5. The stage in which the free 

 individual has become attached by the 

 extremity which was formerly joined to 

 the stalk at ^. The peristome and disc 

 are again everted ; the process of this 

 latter change is carried on very slowly. 

 The condition here represented is at- 

 tained about forty-eight hours after the 

 free state is assumed. 



