238 A. C. OUDEMANS, NOTES ON ACARI. 
parts. Especially the textüre of the sterno-metasternal shield 
(fig. 8) is characteristic: each scale is viz. longitudinally striated, 
but the striation generally does not touch the edges of the scales. 
Dorsal side (fig. 1) partly protected by two shields, 
both are equilateral triangles, with rounded and slightly con- 
vex sides. The anterior one generally protects the anterior 
half of the creature’s back; the posterior one is much smaller, 
which is the more conspicuous as the posterior half of the 
creature’s back has a greater surface than the anterior one; 
so that there is a very wide unprotected margin around the 
posterior shield. In swollen specimens, like that drawn by 
me, there is also a very narrow unprotected margin around 
the anterior shield. Between the two shields there is a rather 
wide band of unprotected and bare skin. Before the anterior 
shield, above the coxae I the peritremata are visible, 
Hairs; all the hairs may be called bristles, but there are 
three kinds of them. Firstly we observe 3 pair of long 
and strong ones, as I have delineated in fig. 4; they are 
distally somewhat hairy; one on each shoulder; the second 
pair in the middle of the anterior shield a little before the 
level of the shoulder-hairs; and the third pair in the anterior 
half of the anterior shield. The distance between the two 
hairs of the last mentioned two pairs is about equal to that 
between one of the two hairs and the nex lateral edge ofthe 
shield. Secondly on the anterior shield on the usual places 
about 14 pairs and on the posterior shield on the usual places 
about 15 pairs of long bristles. Thirdly around the poster- 
ior shield, parallel to the edge of the abdomen, 5 rows of 
very small bristles, together about fifty pairs of them, and 
one pair flanking the vertical hairs. 
Ventral side. Tritosternum (fig. 5) long, a little con- 
cave at the sides, distally (fig. 6) bluntly pointed, and here 
provided with minute hairs directed forward. This distal triangle 
lies over the attachment of the laciniae to the trunk. 
