24 Gr- O. Sårs. 



pearing in the course of a few weeks. After some time the 

 reproduction gradually diminished, and the greater number 

 of the specimens now turned out to be gamogenetic, exhi- 

 biting traces of the characteristic ephippial formation. At 

 the beginning of this period, male specimens were found in 

 considerable numbers ; but their existence was of rather short 

 duration, and at the close of the season scarcely any 

 could be detected. Meanwhile newly formed ephippia 

 had been deposited by the females, and were found in con- 

 siderable numbers at the bottom of the aquaria. From some 

 of these I at once collected the bottom-deposit, and kept 

 it for some time in a dried state, then again placing it 

 in a newly prepared aquarium, and, although the duration of 

 time seemed to be insufficient, a new series of generations 

 was obtained in this manner, in the very same season. I 

 have tried this experiment several times with good success, 

 and have thereby been enabled to obtain an almost inde- 

 finite number of specimens of this beautiful form. 



In habits, this Clodoceran is a true bottom-form, and in 

 its native home, it would seem, prefers shallow lakes 

 with rich vegetation. Indeed, it was only in aquaria in 

 which numerous aquatic plants were growing, that it de- 

 veloped in any numbers, whereas it did not seem to thrive 

 when there was a lack of vegetable matter. It is by no 

 means an active animal, being more frequently found 

 clinging to plants growing in the aquaria, or to the 

 walls of the vessel. Sometimes it is seen slowly ad- 

 vancing along the stalks or leaves of the aquatic plants, with- 

 out ever moving its antennæ. This creeping motion is ex- 

 clusively effected by the aid of the 2 anterior pairs of legs,: 

 the claw-like spines of which grasp the plants. It also at 

 times moves freely in the water in a somewhat jerky manner, 



