S76 
ON THK ACAllUS, 
nearest to tlie body, is partly surrounded by a little hard sheath, 
in and out of which it moves at the animal’s pleasure. The joints 
themselves consist of a firm parchment-like substance, with a 
fine scaly cover, which is far harder than the skin for coat 
of mail) on the trunk. The two first joints are each fur¬ 
nished with a tolerably long hair; the third joint has two shorter 
hairs; and on the fourth is found, near to three hairs, a sharp 
horny claw curved downwards and backwards, and near to that 
are the suckers (cccc) beforementioned. Each of these suckers 
has a stalk-like projection which is in length about the fourth 
part of the whole foot; and its thickness, when it is viewed 
under a microscope, appears to be double that of one of the hairs 
of the feet. It has three joints, and at its commencement under 
the claw of the last joint is very moveable. The suckers consist 
of a fine transparent skin, and are in their extended state three 
times as wide as the stalk, but when in their contracted state 
they are not perceptibly wider. 
The four hind feet are situated two on each side of the trunk, 
somewhere about the commencement of the last third part of it, 
and fixed in such a manner, that one is directed outwards, and 
the other inwards and under the body. In the male acari the 
outer hind feet (ee) are placed quite at the outer edge of the body. 
They are as long as the whole body, and as thick, and formed in 
the same manner as the fore feet. They have at their end a sucker 
and a couple of very stiff hairs, one of which is more than twice 
as long as the whole body. It is crooked in different directions, 
and when the animal moves is usually trailed after him. The 
inner hind feet (//) of the male are formed in the same manner 
as the outer ones, but are rather weaker and shorter; the end 
hair is only as long as the foot itself, and the suckers are 
wan tin g. 
The male insects can only be distinguished by two small round 
dark spots on the under surface of the body, on each side of the 
middle line, and near to the hind parts (g). The last are found 
at the end of the body between two warty lumps which are covered 
with hairs ; but neither the lumps nor the hairs are half so 
strong and so long as they are in the female. The female insect 
(fig. 2) is in the head {a) and the fore feet (bbbb) exactly like 
the male ; the body (d) is, however, one-third longer than that of 
the male (about one-ninth of a line long), almost a perfect oval, 
and not so lumpy as the body of the male. Both the hinder 
feet are placed under the body near to one another. They are 
of equal length and thickness, but much shorter and weaker 
than those of the male, being only onc-seventh as long as the 
body. The outside hind feet {ce) have likewise two equally long 
