14 NOTES ON 
on entomology have classed the larve with 
fresh water shrimps, under the name of Squille 
aquatice. 
The body of the perfect insect is short, and 
furnished with wings, covered by shelly cases 
(elytra). Ithas two compound eyes, and is am- 
phibious; it, however, seldom takes flight or 
leaves the water in the day-time. The feet, which 
are long, have the tarsi composed of five articu- 
lations. The four anterior feet of the males in 
the larger species (marginalis), are furnished 
with spongy cups. They swim with great 
rapidity by the assistance of the hinder legs, 
and being sharp-sighted, pursue every aquatic 
insect within their reach. 
Modern entomologists have divided these 
pentamerous insects into several sub-genera, 
and enumerated various species in the perfect 
state, the systematic distinctions of which it is 
not the province of this work to describe. The 
difference between the. smaller species (which 
are numerous), in the larva state, is unknown. 
I am inclined to believe that this subject is the 
Dytiscus minutus of Linné, or the Laccophilus 
minutus of Dr. Leach. These larve, when pre- 
served in Canada balsam between slips of 
glass, become permanent microscopic objects. 
