X 
F. Scales scattered; size of scale, 1.5 to 3 mm. aesculi. 
FF. Scales arranged in clusters, meeting on cephalic margins; size of 
scale, 1.4 X 1.3 mm. ancylus. 
EE. Exuvia; yellow, covered with white; scales light yellowish brown. 
uvae. 
CC. Spinnerets wanting; scale convex; exuvia: orange yellow, covered with 
white. 
Chionaspis. 
A. Inner margin of median lobes widely separated. 
B. Median lobes parallel, separated by one-third width of lobes. pinifoUac. 
BB. Median lobes diverging from base. 
C. Posterior group of 2d row of dorsal glands absent; minute circular glands 
absent (see Plate XV, fig. 1) ; male scale not carinated. platani. 
CC. Posterior group of 2d row of dorsal glands present; minute circular 
glands present; male scale tricarinated. (Plate XIV, fig. 1.) 
salicis nigra e. 
AA. Inner margins of median lobes close together. 
B. Inner margins of median lobes fused; 2d row of dorsal glands absent; scale 
broadly convex. americana. 
BB. Inner margins of median lobes separated, but almost contiguous. 
C. 2d row of dorsal glands absent; scale flat or slightly convex; male scale 
tricarinate. furfura. 
CC. Only anterior group of 2d row of dorsal plants present; scale quite con- 
vex; male scale not carinated. ortholohis. 
LECANIINAE. 
Under this subfamily there are two genera represented, Uecanium and Pulvinaria. 
In both the female is naked. In the former the eggs remain under the body of 
the female, while in the latter a cottony ovisac extends posteriorly from under the 
body of the scale. The larvse of both sexes in this subfamily have a pair of large 
anal lobes. (See Plate XVI, fig. 3.) At this stage they possess well-developed 
legs, and are active. Later, when these young scales have settled down, these legs 
and the antenna: become functionless, and may be observed in the bleached body 
or test of the adult insect. Further details are brought out in the discussion of 
the characteristics of the various species. 
Leeanium . 
A. Scale with 2 prominent tubercles. cockerelU. 
AA. Scale without tubercles. 
B. Seale dark brown or black. 
C. Antenna six-jointed. kansasense. 
CC. Antenna 7- or 8-jointed. 
D. Scale with ridges forming H, small ridges extending half-way up from 
margin; 2 tarsal digitules. oleac. 
DD. Scale without ridges forming H, caudal part of body plicate; only one 
tarsal digitule. canadense. 
BB. Scale light brown or yellowish brown. 
C. Scale low or nearly flat. 
D. Seale low, convex, pitted around fusiform median surface and on sides of 
scale, sides in folds and depressions; caudal margin plicate. 
aurantiacum. 
