Mr. andre’s Microfcopic Defcription, &c. 441 
part of a woman’s bonnet. The eyes are a part of the fhell, 
or, as linn;eus expreffes it, they are tejlce innati *. They 
may be diftinguifhed by the terms large and fmall, or lateral 
and anterior. If the fhell were divided fairly in half, the large 
eyes would be nearly in the center of each piece, and the 
fmall ones on the divided edge near the fore-part of the fhell. 
The large eyes are at a great diflance from each other ; but the 
fmall ones are clofe together. It will appear hereafter, that 
the large eyes are made up of a great number of fmall, tranfpa- 
rent, amber-like cones, and that the fmall ones are compofed 
of one fuch cone only ; fo that they may be divided into eyes 
with many cones, and eyes with a fingle cone -j-. The large eyes, 
or thofe with many cones, appear as two tranfparent l'pots 
about the fize and nearly of the fhape of a kidney bean, the 
concave edges looking towards each other, and the convex 
towards the edge of the fhell. If they be examined atten- 
tively, we may difeern on their furface a number of fmall de- 
prefiions, which point out the center of each cone. The 
fmall eyes, or thofe with a fingle cone, look like two fmall 
tranfparent fpots, not larger than a pin's head ; thefe, from 
their minutenefs, are eafily overlooked, fee fig. 1. where A.A. 
fhew the large eyes, and B.B. the fmall ones. 
The appearances which I have deferibed may be feen on the 
external furface of the fhell with the naked eye ; but in order 
to proceed to a further inveftigation of the fubjedt, the cor 7 :c<z 
* This being the cafe, tjie eyes can enjoy no motion ; in which particular, as 
well as in lome others, the Monoculus Polyphemus differs from the genus of crabs, 
whofe eyes are placed on petioles, or ftalks, and are moveable. 
f The Greek words coU'? xa w,-, and ^ 0 »o; xuvoc, would exp refs the fenfe in a more 
concife manner. Ocul'i polycotiict et oculi monocomci. 
Vol. LXXII. * M m m 
muft 
