1006 -The American Naturalist. [December, 
uations. In the prairie regions of central Illinois, where 
nearly all of the country is occupied by corn fields and Osage 
orange hedges, the young are very common on the corn 
plants, where, as I have elsewhere surmised, they probably live 
upon the numerous small insects drowned in the moi 
contained in the bases of the unfolding leaves, as well as.on 
the corn plant lice (Aphis maidis). The full grown individuals 
are to be found nearly everywhere, on bushes and trees in the 
woods, in meadows and pastures, along fences, and in sheds 
and outhouses. They occur abundantly from July to October. 
The only opportunity I have had of studying the long-legged 
southern form in the field was in southern Illinois during the 
autumn of 1886. Along the rocky ledges running across the 
State and through Union County, these harvest-spiders were 
exceedingly abundant, occurring everywhere on the rocks and 
ground. They were so numerous that as one walked in the 
open groves on the farm of Mr. Parker Earle they would run 
along in droves. 
This species, like others of its family has the power of exud- 
ing from about the coxæ a liquid with a peculiarly disagree- 
able odor. This doubtless serves as a protection from birds and 
other enemies. 
An idea of the difference in length of legs between the 
species as it exists in Dakota and Mississippi may be obtained 
by comparing Fig. I, Plate XXIX, with Plate XXVII, the first 
representing a specimen from the former locality, and the 
second, one from the latter State. The structural details of the 
two sexes of the southern form are represented magnified at 
Plate XXIX. In each figure, a represents the body with legs _ | 
detached; b, a side view of the eye-eminence; ¢, a front view 
of the same; d, a side view of the palpus; and ¢, a side view. 
of the palpal claw. The row of teeth-like tubercles on the 
inner border of the last joint of the male palpus do not show 
in the position from which the drawing was made. The ahd 
engravings were made from drawings by Miss Freda Dene c - 
DESCRIPTION. a aa 
The southern form of this species may be described as fol- 
lows: i a 
