{71 
PLA TE EL. 
es ete 
MONOCULUS QUADRICORNIS. 
APTERA. 
GENERIC CHARACTER. 
Legs from four to eight, formed for fwimming, and very long: 
ody covered by a fhell divided into fegments: Antennz either four,: 
two, or none; eyes one, or two, approximate and fixed in the fhell: 
eelers four, and in continual motion when {wimming : pofterior ences 
Very fmall and hooked. _ 
SPECIFIC CHARACTER. 
Antenne four: tail ftraight and bifid; the divifions ramofe. 
Although this infe&t may have been noticed by many, fwimming, or 
father darting fwiftly in various direétions in water ; its minutenefs is 
luch, thatthe moft attentive could never have comprehended precifely 
oe Se pee parts. The microfcope difcovers it to be an animal 
Ree uch fingular formation as highly to deferve the attention of the | 
Aturalift, It is covered by a hard fhelly fubftance, divided into 
aren and. armed in feveral parts with {pines aud briftles; not- 
: : anding which, this thell is fo tranfparent that the whole motion 
the inteltines is very vifible by a good magnifier. © 
B4 a It 
