14 Gr. O. Sars. 



Biological Observations. 



Several specimens of this Phyllopod were reared in my 

 aquaria, and they were watched nearly every day during- 

 the whole summer. They became sexually mature after the 

 lapse of about a month, but had at that time scarcely 

 attained half their definitive size. The shedding of the skin 

 was effected at rather short intervals during the whole 

 time in which they were observed, and at each exuviation 

 the animal increased considerably in size. It was seen 

 to feed eagerly upon the smaller forms of Entomostraca 

 developing in the aquaria, and also to beat off the soft 

 parts of aquatic plants growing on the bottom. In order 

 to secure the undisturbed development of the other Ento- 

 mostraca, which were also objects of my investigations, 

 I transferred the greater number of the specimens to a 

 single aquarium, feeding them, as a rule, every day with 

 some soft parts of aquatic plants, which I had found that 

 they devoured with great appetite. Indeed they seemed 

 to thrive very well on this aliment, and increased rapidly 

 in size, though the water in the aquarium became at last 

 very turbid, partly from their excrements, partly by their 

 constant stirring up of the loose muddy deposit from the 

 bottom. The turbid state of the water prevented me from 

 watching- the specimens more closely; but whenever some 

 fragments of plants were thrown into the aquarium, they at 

 once came up to the surface seizing- with greediness the 

 articles between their leg-s, and, sinking down to the bottom 

 with their booty, they devoured in a very short time all the 

 softer tissues. Hoping- in this manner to rear the specimens 

 to full growth, and perhaps also to secure the deposited 

 eg-gs for subsequent hatching experiments, I continued these 



