110 MODERN CLASSIFICATION OF INSECTS. 



by Geoffroy, and, until recently, the group has been kept entire. From 

 this family they are at once distinguished by the shortness of the an- 

 tennae, whilst the shortness of the palpi and the structure of the legs 

 separate them from the other water beetles, Hydrophilida}. Latreille, 

 indeed, in his Genera, &c., separated them from these groups, uniting 

 them with the Parnidae, in a family to which he gave the name of 

 Otiophori ; but he was subsequently convinced that their relationship 

 with the last-named family was merely one of analogy ; and even in 

 his Genera, he suggested that they formed the connecting link be- 

 tween the Dyticidae and Hydrophilidae. a situation now assigned to 

 them by British entomologists. 



Mr. MacLeay, in the Annulosa Javanica, proposed the separation 

 of some of the large exotic species, in consequence of their apparent 

 want of a scutellum ; and, still more recently, Messrs. BruUe, Laporte, 

 and Eschscholtz have introduced numerous other genera. 



The species of this family are very limited in number, not more 

 than fifty or sixty existing in collections ; some of the species are 

 found upon the margin of the sea, whence, indeed, one species (G. ma- 

 rinus) acquires its specific name. One species (G. limbatus) has been 

 communicated to me by M. A. Lefebvre, by whom it was discovered 

 near tiie summit of Mount Etna, in the region of perpetual snow. 

 Other species are very widely distributed, especially certain Dyneu- 

 tes, all of which ai*e strangers to Europe, but inhabit the remainder 

 of the Old Continent. The genus Gyrinus appears more exclusively 

 to inhabit Europe and North America. I have, however, received 

 several species of the last-named genus from Messrs. Desjardins and 

 Templeton, which inhabit the island of Mauritius. 



The type of the genus Gyrinus is the well known Whirlwig, or 

 Water-flea ; that of Orectocheilus is a curious insect, which appears to 

 be less gregarious than the other species. Nicolai says of it, " In su- 

 perficie Salae frequens, nocte vividus videtur." (^Dissert. Inaug- p. 36.) 

 According to some observations made by M. Robert of Liege, and 

 communicated by M. V. Audouin to the Entomological Society of 

 France, this species is only to be observed running about on the sur- 

 face of the water during the night, hiding itself under stones on the 

 banks by day, and even, if forced into the water, immediately striving 

 to gain the shore, never diving, like the other species, to the bottom. 

 Mr. Howitt has also published some observations on this species in 

 his Book of the Seasons, and which, together with the circumstances 



