Ewing — New North American Acarina. 75 
sessing four rather long bristles, three at the distal end of the segment 
and one near the middle; about half a dozen other very minute bristles 
present. Claw of tarsus I stout, somewhat longer than the width of the 
segment. Tibia of leg I almost as broad as long and possessing a long 
tactile bristle about three times as long as the segment itself. 
Length, 0.40 mm.; breadth, 0.22 mm. 
Under a log. Collected by the writer at Arcola, Ill. 
This species is noted especially for the large size of the 
bristles on the body. 
RHIZOGLYPHUS Claparéde. 
Integument not granular; mandibles chelate; suture dividing the 
cephalothorax from the abdomen; only two large posterior bristles on 
the dorsal surface of cephalothorax; ventral apertures small; male with 
anal suckers; in some cases a dimorphic male may exist with the third 
pair of legs enormously developed. Tarsi short, stout; with some stout 
spines and distinct claws. 
One species. 
Rhizoglyphus oblongus N. sp. 
Pe, ATL fe 89: 
Dull, brownish grey; legs paler. 
Cephalothorax long, about twice as long as broad. Mandibles stout, 
their length, as seen from above, equal to about one-third that of the 
cephalothorax. Anterior bristles slightly curved, situated on the 
anterior margin of the cephalothorax and extending to almost the tip 
of the mandibles; the two posterior bristles as long as the cephalothorax 
itself and situated near the lateral margins of the same; a very small 
pair of bristles is present between the large posterior bristles. 
Abdomen large, almost twice as long as broad and possessing few 
prominent bristles; the largest pair being the shoulder bristles, which 
are almost as large as the posterior bristles of the cephalothoray. 
Besides the shoulder bristles there is a pair of lateral bristles about one- 
half as long as the shoulder bristles situated about two-thirds the dis- 
tance from the anterior to the posterior end of the abdomen, also a pair 
of similar posterior marginal bristles and a pair of bristles situated 
dorsally about their length from the posterior margin. 
Tarsus of leg I half as long again as the tibia; sense hair situated 
about two-thirds its length from the proximal end of the segment. No 
large spine near the sense hair, there is however a very small spine, 
about two-thirds as long as the sense hair itself, situated approximate 
to it on its inner side. Just above the tarsal claw is situated a very 
large, stout spine about two-thirds as long as the claw itself; on the 
inner margin of the tarsus about one-third the distance from the distal 
to the proximal end of the segment is a small, sharp spine directed for- 
ward; just posterior and dorsal to this spine is a long slender one 
about three times as long; on the outer posterior aspect is situated a 
small spine. Distally the tarsus of leg I bears two lateral and one 
