151 
tibia and tarsus. The first three pairs of legs consist of six joints 
in Eupodes, the femur of the fourth pair of legs is in Eup. fusifer 
R. Can. divided by an indistinet groove into a large proximal and a 
small distal part. In Eu. variegatus Koch the two parts are sepa- 
rated from each other by a distinct articulation (Berlese I Tab. 24 
—25). The fourth pair of legs in the last named species have 
consistently seven joints. The three first pairs of legs in Norneria 
gigas R. Can. consist of six joints; the femurs are divided into ” 
two parts by a groove; the fourth pair of femurs is divided into 
two joints by a distinct articulation. The legs in Linopodes Koch 
all consist of seven joints (not numbering the one tarsal piece) as 
the fourth pair in Norneria. The first pair is very long and slender 
and used as feclers. The three last pairs are shorter ambulatory 
limbs and by more or less distinct circular grooves their tarsi are 
divided into two pieces. The two last joints in the first pair being 
separated from each other by a ginglymous articulation and not 
by a mere groove as the two tarsal joints of the other legs, there 
is scarcely any cause to identify the penultimate joint of leg I with 
the proximal tarsal part of the other legs (Berlese 1 Tab. 26) 
or the fourth joint (pars. distalis femoris) of the first with the tibia 
of the other legs. The basal part of femurs IV is by an indistinct 
groove divided into a very short proximal part and a much longer 
distal part. The legs in more developed genera as Actineda Koch, 
Ryncholophus Dugås and Trombidium Fabricius, consist as in Lino- 
podes of seven joints the femurs always being bipartite. The tarsi 
are sometimes provided with false articulations as in the Phalangiidae 
(Erythraeus Hercules) (Berl 1 Tab. 117) and E. sp. from Finland. 
The legs of at least many higher Prostigmata are thus divided 
into seven joints, and the third and fourth joint of these correspond 
to the third in many other lower members of the same suborder. 
Such a division of the femurs into different joints is, as far as I 
know, only found in the Chelonethi outside the order of the Acari. 
In this order, as Hansen has made evident, we are able to follow 
the gradual development of this division from Chiridium to Chtonius; 
