STATES OF INSECTS. (Larva.) 139 
have either ten, eight, six, or two prolegs, seldom more 3, 
and never fewer. Of these, with a very few exceptions, 
two are attached to the last or anal, and the rest, when 
present, to one or more of the szzth, seventh, eighth, and 
ninth segments of the body: none are ever found on the 
fourth, fifth, tenth, or eleventh segments. 
1. Where ¢en prolegs are present, as is the case in by 
far the greatest proportion of Lepidopterous larvze, there 
is constantly an anal pair, and a pair on each of the four 
intermediate segments just mentioned. 
2. In caterpillars, which like those of a few species of 
the genera Sphinx, Pyralis, and of the Bombycide, &c. 
have eight legs, they are placed in three different ways. 
In those which have an anal pair, the remaining six are 
in some fixed to the sixth, seventh, and eighth ; in others, 
to the seventh, eighth, and ninth segments. In those 
which, like Cerwra Vinula, and several other species of 
the same family, have no anal prolegs; the whole eight 
emerge from the sixth, seventh, eighth, and ninth seg- 
ments. 
3. The Hemigeometers, as Plusza Gamma, &c. have 
only siz legs: namely, an anal pair, and two ventral ones, 
situated on the eighth and ninth segments. 
4. The larve of the Geometers (Geometre F.) have 
but four prolegs ; of which two are anal, and two spring 
from the ninth segment. It should be observed, how- 
ever, that the larvae of Hemigeometers, and even of some 
of those that have ten prolegs, where the four anterior 
ones are much shorter than the rest, move in the same 
@ Some few subcutaneous larve have more, as that before men- 
tioned, observed by De Geer in the leaves of the rose; which has 
eighteen prolegs, and no true ones. 
