Ewing — New North American Acarina. 69 
of the male is the thickest segment; the genual, however, is almost as 
stout and bears on its inner dorsal aspect an enormous horn of a very 
characteristic shape and which is fully as long as the segment itself; 
tibia about one-half as broad -as the genual and possessing a prominent 
quadrate horn on its inner side; tarsus of the usual size. Caruncles of 
the tarsi of all the legs rather slender. Legs sparsely clothed with 
hairs. 
Length, 1.10 mm.; breadth, 0.70 mm. 
Under the bark of a rotting maple log. Collected by 
J. D. Hood at Lyons, Ill. 
; UROPODIDAE. 
Body with coriaceous integument, usually much depressed and often 
possessing impressed foveze on the ventral surface for the reception of 
the legs when folded under the body. Mandibles chelate and retractile. 
First pair of legs inserted within a common body opening with the 
mouth parts. Nymphs possessing an anal pedicel composed of excreted 
material for adhering to the integument of insects. Not usually true 
parasites. 
URopPopDA Latreille. 
Ventral surface of the body showing deep sculptures for the reception 
of the legs; body outline oval, not broken; dorsum sometimes pitted but 
never sculptured; leg I possessing claws. 
Five species. 
KEY TO SPECIES. 
1. Integument of body deeply and uniformly pitted, pits large 
U. cribraria. 
Integument of body smooth 2; 
2. Body uniformly rounded behind ay 
Body pointed behind U. folsomi. 
3. Antero-lateral margin of body convex U. illinoiensis. 
Antero-lateral margin of body concave 4, 
4. Body almost as broad as long . U. fusca. 
Body about two-thirds as broad as long U. pallida. 
Uropoda cribraria n. Sp. 
Fe Ae p29: 
Brown; integument very coarsely pitted, giving the whole body a 
sieve-like appearance. 
Body oblong, uniformly rounded behind and somewhat pointed in 
front, with a row of stout curved bristles around the margin. Female 
genital plate much more finely pitted than the rest of the body, about 
three-fifths as broad as long and extending from behind the coxxe of 
the last pair of legs to between the second pair of legs. Male genital 
opening on the median line half way between the third and fourth 
pair of legs. 
Anterior pair of legs scarcely one-half as long as the body; tarsus 
of leg I almost as long as the three middle segments and well clothed 
