HYDROPHIL. 
96 
observed to prey on the smaller kind of water- 
snails, and is distingiiisijed by a particularity in 
the highest degree remarkable: this consists in 
the apparently anomalous situation of the legs, 
which seem, unless very accurately considered, to 
be placed, not beneath the thorax, as in other 
insects, but on the ujjper part, and from thence to 
be deflected towards the sides. This uncommon 
appearance however is not owing to a real dorsal 
insertion of the legs, but principally to the peculiar 
shape and position of the head; and the deception 
is so much heightened by the inverted posture in 
which the insect generally swims and rests, that it 
is by no means easy, even for the most scientific 
observer, to divest himself of the erroneous idea 
before-mentioned. Frisch, in his History of In- 
sects, appears to have been completely convinced 
of the reality of the dorsal insertion of the legs; 
and the celebrated Reaumur, having discovered 
something similar in another aquatic insect, was 
so struck with the unusual appearance, that he 
has commemorated it as a circumstance unparal- 
leled in the animal world. The author of the 
fourth volume of Seba’s Thesaurus was of the 
same opinion, and expressly warns his readers that 
his engraver, thinking to rectify what he supposed 
an erroneous drawing, has represented the legs in 
this larva as situated beneath the thorax and not 
on the upper part. The sagacious Lyonct, in his 
observations on Lesser’s “Theologie des Insectes,” 
seems to have been the first who detected the 
