626 IVAR TRAGARDH 
fold runs across in an even curve backwards. The anterior median part at 
the base of the pseudocapitulum has the cuticle finely reticulated by very 
minute, semispherical projections which are arranged in transverse rows. By 
means of this structure the pseudocapitulum seems to be capable of being 
retracted and protruded, as is probably the case in 2. antarcticum TRAGARDH, 
which has a quite similar structure. | | 
The crista metopiea does not end in any well defined anterior area 
sensilligera, but is linear and has only at the posterior end a rather indefined 
area. It extends backwards to a level with the posterior eye-shaped structures. 
The anterior tactile hairs are flanked by two pairs of straight, blunt bristles 
which are about 3 times as big as the body hairs. | 
Eyes. As pointed out above, there are two pairs of eye-like structures, 
but a lens is only developed in the anterior pair, where it is very highly 
convex. 
Mouthparts (fig. 165). The palps: Ist joint very short, slightly curved 
and clavate, with 3 straight paralell bristles in the anterolateral angle; 2nd joint 
large, longer than the 3rd joint and twice as long as it is high, with convex 
dorsal and almost straight ventral edge, with 4—6 long, straight bristles sub- 
marginally and ventrally on the exterior side, 6—8 curved hairs dorsally and 
marginally and a similar number on both sides; 3rd joint curved very sharply 
downwards at the base, the basal portion being concealed within a fold at the 
top of the 2nd joint; 3rd joint — except for the curve at the base — straight, 
3 times as long as it is high, and scarcely half as high as the 2nd joint, with 
numerous, short, slightly curved hairs; 4th joint very short, with fairly slender 
and slightly curved claw; 5th joint narrow, of uniform width, rounded at the 
top and exactly as long as the claw, with 7—8 small hyalin hairs on the ventral 
side and at the top. 
The size and the proportions of the legs is seen in the accompanying 
table. The tarsi and the top of the tibia have a structure which is of special 
interest (fig 166). The dorsal part of the anterior edge of the tibia is shaped 
as a kind of condylus and the corresponding part of the base of the tarsus is 
deeply excavated like a socket. In this way it is possible for the mite to 
bend the tarsus upwards at a right angle, an acomplishment which may be of 
some use during its locomotion. 











Length of joints (in ») 
Leg 2 a Total length 
I 2 3 | 4 5 6 
! | | | | 
I 126 4 160 270 330) a clls 7290)" Vi 180 . | 1356 
II | 81 | 81 162 180 | 198 108 810 p 
I 63r , | 72 162 Pop pay] Peel 108 846 
IV 90h, \| L3i ics, MM EEZA ST uals eeZOOl4 weal R200 108 1116 » | 
Loc.: Juan Fernandez, Masatierra. 
