New Yorx AGRICULTURAL EXPERIMENT STATION. 301 
dibles, which serve for puncturing. On each side of the rostrum 
there is a three-jointed maxillary palpus used as an antenna. The 
second segment of the palpus has on its dorsal side one hair. Close 
to the rostrum there are two pairs of legs, one pair to a side, which 
are of similar size and shape. These project forward and are five 
segmented. A few small hairs are usually present on all but the 
basal segment, which are constant. Segment 2 has a short fine 
hair, segment 3 has a long stiff hair, and segment 5 has one long 
hair on the outer margin and a small one on the inner margin. The 
apical segment also has a small cylindrical claw which is sometimes 
swollen at the tip. Beneath the claw is a plumose hair, called a 
feathered hair, which ordinarily has four or five rays. In the region 
about the base of the rostrum and between the legs are three pairs 
of hairs, known as thoracic setae I, 2, 3, respectively. The dorsum 
of the cephalothorax has one pair of hairs, the dorsal setae, and is 
often marked with sculptural designs which afford important taxo- 
nomic characters. 
The abdomen is cylindrical and is transversely striated, giving 
the appearance of narrow rings. The number of striae may vary 
with the species. With some species the body is evenly ringed all 
round, and in others the number of rings on ventrum is larger than 
on dorsum. Between the rings are frequently small tubercles 
which are only apparent when highly magnified. At the extremity 
of the abdomen are two semicircular flaps, which may be at will 
brought closely together or withdrawn, and which serve for pur- 
poses of grasping and locomotion. Below the flaps is the anal open- 
ing. The genital openings are situated on the ventral surface of 
the abdomen close to the thorax. In the female the external por- 
tion, the epigynium, consists of two parts, a semicircular opening 
with a raised chitinous margin and a flaplike cover, while that of 
the male, the epiandrium, is smaller and appears as a simple open- 
ing, sometimes arched shape, with thickened margins. On the 
dorsum of the abdominal flaps there are two long whiplike bristles, 
the caudal setae, and usually two accessory hairs which are short 
and stiff. The abdomen has five other pairs of bristles. One pair 
is at the sides of the genital opening and is known as the genital 
setae. Near the margin of the body, beyond the genital opening, 
is one pair of lateral setae. The remaining pairs are also on ventral 
