224 
by the basis it increases in thickness almost out to the 
apex and is divided into a longer basal joint, 
pars basalis femoris (d), and a shorter distal 
joint, pars tibialis femoris (e), being but a little 
shorter than the tibia; the articulation between the 2 parts 
of femur is in all essential points of the same structure 
as between femur and tibia, that is to say, allowing a 
movement in the vertical plane, but the articular mem- 
brane is not !/; as broad as that between femur and 
tibia. In Obistum (Tab. IV, fig 15) we find a similar 
structure as in Garypus, showing, however, a further 
development in the tendency that pars tibialis femoris 
(e) is working as a supplementary tibia, for we find that 
the articular membrane on the lower side between the 
2 parts of femur is broader than in Garypus, that 
according to the shape pars tibialis femoris does not 
appear to be a part of femur and is not thicker than 
pars basalis, and tibia is less tapering at the basis. 
The tarsi are 2-jointed in Garypus and Obisium (fig. 
14 and fig. 15, h). The structure in Chthonius is 
developed in such a way that I deem it impossible to 
understand it but by means of the preceeding genera, of 
which Garypus (Olpium) also in other respects 
makes an excellent intermediate form between 
Chelifer and Obisium-Chthonius. Pars basalis femoris 
is twice as long as and a little thicker than pars tibialis, 
it is as long as, or but a little shorter than tibia; the 
articulation between the 2 parts of femur is quite as 
developed to movement in the vertical plane as the 
articulation between femur and tibia; tarsus is I-jointed, 
much longer than tibia and very slender towards the 
apex. 
This interpretation differs quite from that of other 
authors. Simon and Balzan take pars tibialis femoris 
for tibia, and thus tarsus becomes 3-jointed in Garypus 
