Marvels of Pond-Life. 135 



distinct ventral and dorsal side. The branches of the 

 tube stopped somewhat abruptly just before reaching 

 the surface, and were often observed to end in small 

 round vacuoles or vesicles. 



At the bottom of the bladder, opposite the mouth, in 

 some specimens were large round cavities or cells, filled 

 with smaller cells, or partially transparent granules. 

 These varied in number from one to two or three, and 

 were replaced in other specimens by masses that did 

 not present the same regular form or rounded outline. 

 In one instance an amorphous structure of this kind 

 gradually divided itself, and seemed in the course of 

 forming two cells, but the end of the process was un- 

 fortunately not seen. The annexed drawing will readily 



Trachelitis ovum (slightly flattened). 



enable the animal to be recognised. It shows the mouth 

 very plainly, and a current of small particles moving 



