132 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
translucent, ochreous-white. Sculpture of dorsum fairly constant, but less pro- 
nounced m a partly engorged female than in the old and shrivelled examples. 
Capitulum (PI. 2, Fig. 3) ; hypostome not much wider at the base than at 
the anterior third, margin converging inwards, teeth 111 three bilateral rows ; 
mandibles (PI. 2, Fig. 4, 4 a), when fully extended, reaching to the second 
articulation of the palpi, digit with a blunt terminal tooth, exterior apophysis 
with two widely separated teeth ; inlerior apophysis bidcntate ; palpi tapering 
towards the extremity second joint much the longest, sides of all the seg- 
ments highly chitinised. Derm cells (Fig. 5, 5a) large, irregularly ovate, 
with one or two extremely minute spines at or near the margin, each cell 
surrounded by a band of dark chitine, the latter character being much more 
pronounced in the region of the posterior margin. Stigmata (Fig. 6) lunular, 
peritreme finely pitted and strongly chitinised. Dermal secretion glands 
(PI. 2, Fig. 7) irregular in outline and variable in size, the subcutaneous 
tubes attached to these organs are branched and appear like bundles of 
muscular fibre ; there is a group between the base of the capitulum and coxa 
1, another between coxa 1 and 2, and a third between coxa 3 and 4, there 
is also a long bilateral series commencing immediately posterior to the 
genital pore. Legs (PI. 2, Figs. 8, 8a, 8b, 8c) normal. Margin of genital 
pore deeply crenulated. 
Nymph (PI. 1, Fig. 8) : Colour, pale ochreous-brown, legs translucent 
white with, in certain lights, a faint, pale ochreous tinge. Form broadly 
ovate. Dorsum thickly studded with minute papillae, increasing in size 
posteriorly, forming a regular crenulated fringe at the margin. Sculpture of 
dorsum somewhat resembling that of the adult females. Capitulum (PI. 2, 
Fig. 2) partly projecting beyond the margin. Hypostome with two bilateral 
rows of teeth, basal pair minute, the remaining teeth are large and equal in 
size ; mandibles strong ; digit blunt, terminal. Palpi broad, stout, third seg- 
ment the shortest, apical segment about equal in length to the second, and 
bears two or three short spines at the tip, all the segments have a broad 
marginal band of dark chitine. Legs (PI. 1, Figs. 9, 9a) sparsely spinose, 
rather long ; leg i. (Fig. 9) of seven segments, Haller's organ present ; legs 
ii.-iv. (Fig. 9a) of eight segments, with the femora more dilated outwardly 
than 111 leg i. Anal orifice placed a little posterior to the insertion of leg i. 
Vaginal orifice absent. Spiracles minute, placed opposite insertion of leg iii. 
Larva (PI. I, Fig. 4) sub-circular ; colour dull purplish-brown, varying 
somewhat in intensity according to the age of the individual ; but at or near 
the period of ecdysis the cuticle becomes more opaque and greyish in tone. 
At this stage, immediately posterior to the anal orifice, is a comparatively 
large, subcutaneous arrow-shaped, or Y-shaped, patch of white granular 
matter, evidently secreted by the nymph, which at this period has reached 
an advanced stage of maturity. Segmentation of legs not clearly defined 
after maceration in potash ; femoral area of each leg with three pairs of 
equidistant spines ; there are also a few isolated spines on the regions of the 
other segments ; terminal tarsal segment (Fig. 5) of each leg broadly 
obtuse ; claws short, stout, and curved. Haller's organ placed immediately 
posterior to the terminal tarsal articulation. Capitulum (PI. 2, Fig. 1) 
within the anterior margin in the earliest stage, but in more mature larvae 
it projects slightly beyond ; base of rostrum on the dorsal area with two 
