144 On the Ti PASE of the Red Mites,  [March, 
various dorsal irregularities, usually about five pairs of circular 
essións connecte y transverse ones on anterior 
two-thirds, and a triangular series posteriorly. Barbed 
Characterized by the penultimate palpal joint forming 
a single claw with a prominent notch, while the ter- 
minal thumb is large, extending one-third its length 
\ beyond the claw, clavate and with the inner side of its 
broad end flattened; the claw as well as the thumb 
ye having sparse hairs: terminal joint of legs squarely 
Pe SS | docked, with the claws reaching but little beyond the 
Trombidium side. ca : : : k 
giganteum, a, Living in the ground. Nine specimens examined. 
“ses pa a We have also reared to the perfect state the 
and thumb. well-known Astoma parasite that attacks the com- 
mon house-fly (Musca domestica) in this country. 
The larva (Fig. 4) has the same mode of trans- 
formation as T. locustarum, but is much more ac- 
tive after detachment, while the gradual shrinking 
and withdrawal of the larval legs during the 
g transformation to pupa is much more easily ob- 
Fig. 4—Larva served. The species is distinguishedfrom 7: /ocus- 
of he: yombidium 
ae tarum by the following characters: 
hee muscarum Riley —Larva distinguished from that 
of T. /ocustarum by the greater relative length of 
legs, and by the hairs on the body being much 
longer and more aon a needa also by the more 
distinct transverse sutures, of which there are 
four. Transverse striations noticeable soon after 
5 ‘attachment. Full grown — also more active. 
Fig. 5.—-Trombid- | Pupa-—More rounded ind, 
sum MOm, 4 Adult Average fengeh 1 1.2 mm.; color bright — 
labial claws and 
thumb; 4, pedal and pale scarlet; legs very pale and with the 
claws; 4 — tu- terminal ‘joint fusiform and the claws much 
berculous hai longer than in T. Jocustarum, and more nearly as 
found in he larva; body rounded, very little narrower behind, 
with no impressions or other marks, Barbed hairs of body 
led appearance under the microscope. Genital depression circu- 
lar; penultimate palpal joint ending in two ery equal, blunt 
its tip. No marked sexual difference 
Many specimens examined. 
The mode of growth of these mites may be more clearly illus- 
