292 PEESH-WATEE AQUAEIA. 



tteir eggs in masses upon stems of plants and sides of stones. 

 The eggs hatcli in about iovx days. The young Cypridce 

 shed their shells frequently as they grow, the exuviation each 

 time being very complete. The eggs have great vitality, 

 and -will survive the drying up of the ponds in -which they 

 have been deposited. 



The members of the genus Cypris — of which C. fusca 

 (Fig. 168) is one of the commonest — are, on account of their 

 swimming powers and active habits, much more iateresting 

 in the aquarium than are those of the other genus, Candona. 

 The CypridcB can be obtained from their native pools in the 

 same way as that recommended for procuring the Daphnice. 



They may be fed while in captivity 

 upon a tiny piece of a garden- 

 worm or a small portion of raw 

 meat. If food is not given to 

 them, they wUl devour one another. 

 These little Entomostraca are very 

 interesting under the microscope. 

 While viewing them in this way. 

 Fig. 168. Cypris fusca (a, much it will be seen how they protect 



ENLARGED : h, NATURAL SIZE). , , , j t 



themselves upon the appearance 

 of any danger, by withdrawing 

 their legs and antennse within the shelter of their pretty 

 shells. And when they think that there is nothing further 

 to fear, the watcher vpill notice how cautiously they protrude 

 their limbs and make preparation for continuing their journey 

 in the drop of water which has been placed with them upon 

 the stage of the microscope. As they are securely inclosed 

 within their shells, their resemblance to tiay mussels will be 

 readily observed. The shells are often prettily marked and 

 coloured, and covered with fine hairs. The aquarium-keeper 

 may take it for granted that all the CypridcB which he captures 

 are females, for the males, I believe, have never been found. 

 These crustaceans are larger than the water-fleas. 



The curious, interesting, and useful Cyclops may be found 

 in ponds, ditches, and slow-running streams, almost every- 

 where. Cyclops quadricornis (Fig. 169) is shaped somewhat 



