208 
and winged female, intermixed with floculent matter and watery 
globules, the insects themselves being rather evenly covered with a 
fine white powder. Later in the season, the tips of the bracts become 
blunter, and the gall becomes browner, and recalls, externally the fruit- 
pod which would have developed the ensuing year. It is now perfor¬ 
ated at some point, generally near either the top or base, and through 
the aperture the insects have either made their exit or may be noticed 
doing so. The young from the winged female are quite characteristic, 
being strongly granulated, and, as they were found as late as the end 
of October, they probably hibernate on the permanent parts of the 
tree. The sexed individuals and the stem-mother are yet unknown. 
The species was first described in 1867 by Dr. H. Shimer of Mt. 
Carroll, Ill., who erected a new genus for it and another well-known 
species on the same plant, not aware that the genus had been pre¬ 
viously characterized by Baron Osten Sacken, in 1861.” 
Pemphigus populi-transversus. Riley. 
Fiff. 47. 
“[Gall ( populi-transversa , Fig. 47,) formed upon the petiole near the 
base of the leaf of Populus monilifera and P. balsamifera. An elon¬ 
gate-oval swelling, causing the curving and broadening of the petiole, 
and opening on the opposite side by a transverse slit, with a whitish, 
slightly thickened, and elevated margin, recalling human lips. By the 
latter part of June the stem-mother is surrounded with young of va¬ 
rious sizes, all covered with the usual white secretion and mixed with 
the liquid globules. Winged females produced in autumn, sometimes 
not until the leaves have fallen.] 
Winged female (Fig. 47, c).—Expanse, 7mm. Pruinescent, with the 
abdomen more yellowish, inclining to green. Antennae (Fig. 47, d) 
reaching a little beyond the base of front wings; smooth; joints three, 
four and five cylindrical, and of equal thickness; three as long as the 
other two together; six more slender at base, and with the apical 
unguis nearly as long as three. Thorax with mesonotal swellings 
small. Terminal distance between first and second discoidal veins of 
