()& HYDUOPHIL. 



that the female of the Hydrophilus piceus affords 

 an example of a faculty which seems to be exer* 

 cised by no other coleopterous insect; viz. that 

 of spinning a kind of web or flattish circular case 

 of silk, which it leaves floating on the water, and 

 in which it deposits its eggs. This case is ter- 

 minated on its upper surface by a lengthened 

 conical process resembling a horn, of a brown 

 colour, and of a much stronger or denser nature 

 than the case itself, which is white. The young 

 larva?, as soon as hatched, make their escape from 

 the envelopement of the case, and commit them- 

 selves to the water. This curious particular in 

 the history of the Hydrophilus piceus was first 

 discovered by Lyonett. 



The Hydrophilus caraboides is a species measur* 

 ing about three quarters of an inch in length, and 

 is of a polished black colour, and of an oval shape. 

 Like the former, it inhabits stagnant waters, where 

 its highly curious farva, admirably figured in the 

 works of Roesel, may not unfrequently be found : 

 it is fringed along the sides with numbers of sepa- 

 rate plumes or feather-formed branchiae. 



The genus Hydrophilus, like that of Dytiscus, 

 has been greatly increased by the persevering re- 

 searches of modern entomologists. Mr, Marsham 

 enumerates twenty-eight British species. 



It may be added that the Hydrophili, like the 

 Dytisci, sometimes emerge from the waters, and 

 fly about the fields, and thus migrate occasionally 

 from water to water; but as v this happens chiefly 

 by night, it is not generally observed. , 



