The Hiflory eJ'A N I M A L S. 
23 
Monoculus a7itennis quaternis , cauda reel a 
bifida . tmMttms 
The Monoculusj with quaternate antenna^ and Hl&tCT 'fluftll* 
a Jlraight bifid tail. 
The creature is very fmall, and ufually of a brownifh, fometimes of a reddifh, co¬ 
lour : the body is oblong, approaching toward an oval figure, but fmaller toward the 
tail: it has two pair of antennas; the tail is long, {lender, and forked, and under 
this, on each fide, there is frequently feen a large clufter of eggs; the ovaries, in 
which thefe are contained, are of a yellowifh colour, and together are often equal to 
the whole body of the InfeCt in bignefs: the eye is large, black, and fituated in the 
very middle of the head. 
It is frequent in our ditches, and other Handing waters. 
Monoculus antennis capillaceis multiplicibus , tefia 
bivalvi, %l)t ttMlZUtS 
The Monoculus , with multiple and capillaceous an- jjJtlfett* 
tennee , and a bivalve Jhell. 
The fhell, with which this creature’s body is covered, is of an oblong, ovated figure, 
and of adufky brown colour: when taken out of the water, it fhuts clofe up, and re- 
fembles the feed of fome plant 5 when put into the water again, it opens in the man¬ 
ner of the bivalve (hells of the fhell-fifh, and the antennae appear from one end of the 
aperture, the legs from the other: the eye is fingle, large, and black 5 it’s motion is 
very fwift. 
It is common in our ditches, and other Handing waters. 
The other fpecies of the Monoculus are, 1. The crooked-tailed Monoculus, with 
dichotomous antenns, commonly called, after Swammerdam, the Pulexaquaticus arbo- 
refeens: this is fmall, of a blood-red, and is fo numerous in Handing waters at fome 
times, as to give a red colour to the whole furface of them ; and this has been called 
turning water into blood, and has been eHeemed a portent. 2. The Apus of Frifch, 
or the Monoculus with a bifetous tail. 3. The fhort dichotomous, horned Monocu¬ 
lus, with the flat back. 4. The long-bodied Monoculus, 5. The little-eyed 
Monoculus. 6. The fhort and multifid-tailed Monoculus. 
ACARUS. 
T H E body of the Acarus is fhort and rounded : the eyes are two; the legs are 
eight in number, and each confiHs of eight joints. 
MoH of the fpecies of this genus have been alfo arranged among the microfcopic 
animalcules, but with no reafon; they are all fufficiently vifible to the naked eye. 
The term Acarus is not to be underflood in this fenfe, as reflrained to the InfeCt com¬ 
monly underflood by it, the Mite : that animal is poflefled of characters in common 
with a great number of other InfeCts, which have been called by ot^er names, but 
which are all connected by nature, and are therefore of the fame genus; fome of them 
have been called fpiders, others lice, and others by other names, referring them to ge¬ 
nera, to which they have as little alliance in nature as to thefe. The genus, on bringing 
thefe back to it, appears a very numerous one, and confifts of fome which are inhabi¬ 
tants of the earth, fome of waters j fome which live on trees, others among Hones, and 
others on the bodies of other animals, and even under their fkin. 
Acarus cafei. 
The Acarus of cheefe. 
This is a very fmall fpecies; the body is roundifh, but fomewhat ovated ; the 
fkin whitifh and fmooth • the head is fmall; the legs and the parts about the mouth 
are fomewhat brownifh, and of a firm, tefiaceous fubftance, not foft like the other 
parts, and there are fome long hairs on the body, 
3 
It 
