302 
Psyche 
[December 
the region of the anterior border of the shield to the region 
above the setal tubercles near the posterior border. The 
dorsal setse (c. 34 microns) arise from the prominent tu- 
bercles at the posterior border of the shield. The legs are 
short and comparatively stout; the tibia and tarsus are 
equally long (c. 6 microns) ; the feathered claw is large and 
five-rayed ; the bristle claw of the first pair of legs is as long 
as the feathered claw while that of the second pair slightly 
overreaches it; the epimera are short; the sternal ridge is 
distinctly bifurcate and reaches to the level of the inner 
corner of the epimera. The first pair of thoracic setse are 
short (c. 10 microns) and stiff, the second pair are of 
medium length (c. 30 microns), and the third pair are very 
long (c. 50 microns). The abdomen tapers slightly in the 
posterior fourth and ends in a small telson that bears the 
long flagellate caudal setse (c. 120 microns) and the short 
(c. 6 microns), acicular accessory setse. The rings of the 
abdomen are broad, about 60 in number, and there are 
numerous tubercles relatively close together on the ventrum 
but usually lacking on the dorsum. The last five rings are 
without any tubercles but have longitudinal striations ven- 
trally. The epigynum is broad (c. 30 microns) with a 
smooth anterior flap and an arched, slightly keeled, pos- 
terior one. The genital setse (c. 25 microns) are more or 
less posterior to the plane of the genital opening. The 
lateral setse arise about three strise posterior to the plane 
of the epigynum and are about the same length as the dorsal 
setse (c. 34 microns). The first pair of ventral setse are the 
longest (c. 75 microns) , the second pair are the shortest (c. 
20 microns) and the most nearly median of the ventral setse, 
the third pair are about 38 microns long and comparatively 
coarse. Measurements of other setse : outer setse c. 30 
microns, maxillary setse c. 6 microns, claw bristle of the 
first pair of legs c. 8 microns, of the second pair of legs c. 
10 microns, femoral setse c. 12 microns. 
Although it does not at any time effect a witch’s broom 
formation, there is another factor to be considered in the 
deformation of the buds of the same hosts as those of E. 
celtis. This is the hemipteron, Pachypsylla gemma Riley, 
which often causes galls involving the deformation of buds 
