those which are ovo viviparous, and give forth their young in an active 
state. They are also wanting in the immature females and the males. 
The San Jose scale is viviparous, and wholly lacks these ventral glands, 
while they are present in the adult females of the allied Aspidiotus 
forbesi, ancylus, ostrecvformis, juglans-regice, &c. They are wanting in 
A. rapax, which however will not be confounded with perniciosus, hav- 
ing a strongly convex scale, with dark sublateral exuvhe. If the 
grouped ventral glands are found, it may be assumed at once that the 
insect is not the San Jose scale; but it does not always happen that we 
have adult females under examination, so their absence, even though 
the scale be iiattish, may not be conclusive. A little study of the 
fc* v 

A. ar\CMlu<J, 
o, i 
A. Wl>nr\;c»oOvi/>. 
A.-fo-rtJXQ.'. 
.Fig. 3. — Aspidiotus juglans-regice, A. ancylus, A. ostrecpformis, A.perniciorus, and A.forbesi (original). 
accompanying figures will,. it is hoped, remove all difficulty. It will be 
seen that in the true Sau Jose scale (A. perniciosus) the median lobes 
are large, upright, notched on the outer margin, though a little variable 
in form, as the different figures indicate. The second lobes are small 
but distinct, quite close to the first, variable in shape but inclined to be 
pointed, and notched also on the outer margin. The chitinous proc- 
esses at the interval between the first and second lobes are well 
developed, close together, and of nearly equal size. Fig. 2 is designed to 
wShow the glandular hairs or " plates; " attention should be called to the 
fact that they are spine-like, at most feebly serrate, not branched ; there 
is a large pair at a and three smaller pairs are shown at b. While the 
