THE ROTUND TICK. 83 
instances and on dog in two cases. Twenty lots have been col- 
lected in which females only were found. The hosts and number of 
lots on each is as follows: Dog, 8; pocket gopher, 2; prairie dog, 1; 
mink, 1; wolf, 1; spermophile, 1; marmot, 1; skunk, 1; kangaroo rat 
(Perodipus richardsoni), 1; unknown, 3. From the large number of 
ticks of both sexesfound on the badger it would appear that that ani- 
mal is one of the more important natural hosts of the species. We 
have been able to engorge the larve experimentally on the guinea 
pig, rabbit, and ox, and nymphs have been engorged on the guinea 
pig and ox. 
GEOGRAPHICAL DISTRIBUTION. 
(Fig. 4.) 
The type locality of this species is Meeteetse, Wyo. The species 
appears to be widely distributed over the Western States from Texas 
to Montana. We have specimens which were collected in Texas, 
New Mexico, California, Utah, Wyoming, Idaho, and Montana. The 
tick appears to be most abundant in the northern part of its range. 
It is quite probable that this species occurs in Canada and possibly in 
Mexico, although no collections have been made in those regions. 
LIFE HISTORY. 
No studies have been made heretofore upon the biology of this tick. 
The egg (Table XX).—Since specimens of this tick have not been 
engorged at the laboratory, only those sent in from various localities 
having been used in our studies, it is not possible to determine defi- 
nitely the relation between the length of the preoviposition period and 
temperature. 
During June and July, 1909, a preoviposition period of 19 days was 
recorded. This is the shortest preoviposition period which we have ~ 
observed. The longest preoviposition period occurred during June, 
July, and August, 1909, and was 65 days. Four other specimens had 
preoviposition periods of 27, 28, 29, and 30 days, respectively. 
Deposition continued from 10 to 36 days. The shortness of the first 
period seemed to be due to the fact that the female was not fully 
engorged. The maximum number of eggs deposited by an individual 
was 4,706, and the average number 3,179. The females live but a 
short time after deposition is complete. 
One female collected on June 23, 1909, began to deposit on the 
sixty-fifth day after collection. During the first 2 days of ovipo- 
sition 454 eggs were deposited. On subsequent days deposition con- 
tinued as follows: 104, 168, 169, 166, 107, 233, 59 (during 2 days), 43, 
44,9, a total of 1,556 eggs being deposited during 13 days. A female 
collected June 29, 1909, began to deposit on the twenty-sixth day 
after collection. On that date and subsequent days deposition pro- 
ceeded as follows: 485, 226, 169, 231, 246, 156, 312 (during 2 days), 
