82 LIFE HISTORY OF NORTH AMERICAN TICKS. 
THE ROTUND TICK. 
Ixodes kingi Bishopp. 
The common name of this species is applied on account of the 
globular form of the engorged female. 
DESCRIPTIVE. 
Adult (Pl. VI, figs. 4-9).—Males 2.85 by 1.51 mm. to 3.15 by 
1.88 mm. Females, unengorged, 2.6 by 1.6 by 0.7 mm. to 2.7 by 1.7 
by 0.7 mm.; engorged, 11.6 by 10.4 by 7 mm. to 13 by 12.8 by 8.5 
mm.; unengorged males and females light yellowish brown; scutum 
somewhat darker; engorged females appear almost globular; shield 
and mouthparts inconspicuous; abdomen light blue-gray in color. 
The grooves on the dorsum and venter practically disappear on 
engorged specimens. 
Nymph (Pl. VI, figs. 2, 3).—Unengorged, about 1.25 by 0.8 mm.; 
length of capitulum 0.37 mm. (from tip of palpi to base of emargina- 
tion of scutum); scutum 0.66 mm. long by 0.68 mm. wide; body 
ovoid, yellowish brown, somewhat translucent; engorged, about 2.3 
by 1.3 by 0.8 mm.; slate color, legs and shield light colored as before 
engorging. 
Larva (PI. VI, fig. 1).—Unengorged, 0.657 by 0.413 mm.; length of 
capitulum 0.19 mm. (from tip of palpi to base of emargination of 
scutum); scutum 0.277 mm. long by 0.335 mm. wide; body ovoid, 
very light yellow, translucent; engorged, 1.19 by 0.727 mm.; bluish 
gray in color. 
Egg.—Ellipsoidal, light yellow, translucent. The maximum size 
of ten eggs was 0.541 by 0.420 mm.; the minimum size 0.528 by 
0.392 mm. and the average size 0.534 by 0.401 mm. 
HOST RELATIONSHIP. 
The type host of this species is the badger. Our knowledge of the 
hosts of the immature stages of this tick is limited owing to the diffi- 
culty met with in rearing immature stages of [xodes to adults, and 
to the fact that the specific identity of the larvee and nymphs of 
Ixodes can not be reliably determined. Immature stages of what are 
very probably this species have been collected upon the following 
hosts: Badger, larve and nymphs; pocket gopher (Zhomomys 
clusius ocius), larve; marmot (MJarmota flaviventer), larve and 
nymphs; skunk, nymphs; dog, nymphs; pine squirrel (Sciwrus hud- 
sonicus richardsoni), larve and nymphs; pika (Ochotona princeps), 
larve and nymphs; chipmunk (Eutamias), larve and nymphs; 
ground squirrel (Citellus columbianus), larvee and nymphs. Many 
of the above lots were collected by Mr. W. V. King in western 
Montana. The sexes were taken together on badger in three 
