the western counties, and is considered a rare and beautiful 

 species. I never have met with it myself, and am indebted to 

 J. C. Dale, Esq., who took it in Dorsetshire, for the specimens 

 figured. 



These insects are to be found in ponds and ditches all the 

 year, together with the larvae and pupae (which are smaller 

 than the imago) : the former are without and the latter have 

 only rudiments of wings ; they are said to feed upon animal- 

 cula : the perfect insect being capable of inflicting a consider- 

 able wound with its rostrum, when taken, must be a formidable 

 enemy amongst the weaker inhabitants of the water. 



The wings, which are exquisitely delicate, and the elytra 

 that protect them, are of little use to the insect in its natural 

 element; but they are necessary to its preservation, by enabling 

 it to seek a more congenial situation, when the place of its ha- 

 bitation is dried up by the heat of the sun, or other casualties. 

 Upon approaching a pond, these insects may be seen lying 

 upon their backs, with their tails touching the surface of the 

 water, and their heads inclined downwards, watching probably 

 for their prey ; and, upon the least alarm, they row off with 

 the greatest celerity, their hinder legs (which are most beauti- 

 fully fringed with long silky hair) serving them like oars, from 

 whence the appellation of Boatfly. 



Cerastium aquaticum (Marsh Mouse-ear) is figured in the 

 plate. 



