286 



CHAPTER Y.— continued. 



ANALYTICAL INDEX. 



Description, . . . . . paoe 252 



Plate LXVII. explained, .... 253 



5. Pegasillus hirsutus, . . . . . ib. 



Did not quite maintain the character of a Crustacean parasite, ib. 



History and description, . . . . ib. 



Plate LXII., explained, .... ib. 



CHAPTER VI.— The Hydrachna, or Water Spider, . . . .254 



The genus Hydrachna described, ... ib. 

 Miiller, Linnajus, ...... 255 



Animals distinguished by eight feet, ... ib. 

 Dwell chiefly in fresh water, .... 256 



Sensitive of heat or cold, .... 257 



Habits possibly modified by situation, . . . ib. 



Pass the uight in profound repose, . . . 258 



Most rapacious, bold, and cruel, . . . . ib. 



Hydrachna ferox, . ... . . ib. 



The Daphnia, or Water Flea. .... 259 



Number of Daphnioe destroyed by the Hydrachna ferox, . ib. 



Hydrachna extendens of Miiller, . . . 260 



Hydrachna placida described, . . . .261 



Food of the Hydrachna; .... ib. 



Breed at different periods of the year — Miiller, M. Duges, ib. 



Spawn deposited on leaves, wood, or stone, . . ib. 



Embryo attain matm'ity in fourteen days, . . . 262 



M. Duges, Annates des Sciences Naturelles, . . 264 



Plate LXVIII., LXIX., explained, . . 265, 266 



Conclusion, ...... 266 



§f & 



