618 THE AMERICAN NATURALIST. [Vor. XXXV. 
of setz. This second row of four small setae extends across 
the middle of the shield-shaped appendage of the reproductive 
organs. The third set consists of two secondary groups, the 
first of which, containing eight hairs, runs across a sort of hem 
attached to the lower margin of the shield-shaped organ. The 
second set is made up of large plumulose spines arising from 
the tips of ten papilla, four of which spring from the edge and 
six from under the edge of the hem. Fig. 3 is a careful camera 
drawing of this region of the male. The first row of setze not 
on the reproductive appendage is not figured. ; 
Segment three in both male and female has on the two blades 
of the reproductive appendages irregularly placed hairs which 
are of varying lengths. In a line posterior to the middle of the ~ 
segment are eight other setze in a row continuing with those of 
the dorsal surface to form the setigerous belt of segment three. 
Most remarkable are the differences between segments four, 
five, and six of X. wheeleri and the corresponding segments of 
K. mirabilis. Concerning the fourth segment of Grassi's species, 
Drs. Hansen and Sorensen have written, * Provided on the ven- 
tral side in front of the middle with a wart-like protuberance 
which bears six stiff setze, almost spines (acu/ez), arranged in 
two transverse rows, the foremost of which is arched and has 
four spines. Grassi seems to consider these spines sen 
organs, an opinion we by no means share.” In K. wheeleri 
segment four is provided on its ventral side with three pairs of 
hair groups. The first pair consists of three long backward- 
pointing setæ on each side of and near the midventral line. 
These setze are situated on delicate chitinous flaps of the integu- 
ment which arise in front of the middle of the segment. T 
second pair is made up of four much shorter backward-curvins 
hairs arranged in an arched transverse row near the middle " 
the segment to the right and left, respectively, of the first pal 
These hairs are most evidently for the protection of the ai 
cate lung sacs when they are ejected, and for protection 0 
their orifices when they are drawn in. The third pair conse” 
of two small setae in the same line and lateral to those - yt 
second group. The former are continuous with the belt o 
sete encircling the whole segment. | 
