130 
Sarcoptes 
The Legs. 
The anatomy of the anterior legs can be understood by reference to 
Figs. 10 and 11. The first and second legs are similar in all respects, as regards 
their size, chaetotaxy and their possession of five joints. More of the base of the 
leg can be seen from below than from above, owing to its ventro-lateral origin; 
the articulation of the first joint with the body is sunk in a pit, just as the 
Figs. 10, 11 and 11 a. Sarcoptes scabiei var. equi. Second left leg of adult female. Fig. 10, 
dorsal, and Fig. 11, ventral aspects. Fig. 11a, ventral aspect more highly magnified, the leg 
slightly rotated so as to show the spur on the second joint, as, stem of ambulacrum; ask, its 
sucker; bd, body; e II, epimere; P 1-10, pedal setae; r, integumentary ridges; sr, spur on 
second joint (“trochantal spur”); 1-5, the five joints of the leg. 
base of the capitulum is sunk in the camerostome. This point has apparently 
escaped notice hitherto, because it is difficult to detect the nearly transparent 
covering of integument with its wide Y-shaped margin. In Fig. 11 a I have 
indicated with dotted lines the part of the first joint of the leg which is so 
covered. In Fig. 2 I have not dotted the corresponding lines, for with a low 
magnification one does not appreciate that these parts are covered at all. 
Actually of course they are extremely close to the surface. The first joint is 
