8 
small pairs of plates are quite characteristic, there is a fair amount 
of variation in these organs, and it is worth noting that if the speci- 
mens are boiled too long they are apt to be destroyed or detached. 
In A. ancylus (fig. 3), the species most commonly confounded with 
perniciosus, it is seen that the shape of the median lobes is different, 
though these organs vary somewhat, and that there is nothing but the 
merest rudiment of a second lobe. It is further seen that the interval 
between the median lobe and the rudiment of the second is very wide, 
and that the chitinous processes are far apart and not of equal size, 
the innermost being the largest. There is also a gland orifice just 
below the intervai. The plates of ancylus, not shown in the figure, 
are fringed and of the type shown in howardi, though less developed. 
A. howardi (fig. 2) is of the type of ancylus, but the rudiment of 
the second lobe is somewhat more developed. The figure, from one 
of the type specimens, 
,  Sufficiently indicates the 
i ‘ characters and includes 
o@ the oval dorsal glands. 
It must be admitted 
that howardi is very 
close to ancylus; per- 
haps only a variety of it. 
A. forbesi (fig. 3) is 
really a good deal nearer 
to perniciosus than is 
ancylus. It will benoted, 
however, that the me- 
dian lobes are more or 
less oblique, and espe- 
cially that the chitinous 
processes of the inter- 
eer ae val between the first and 
Fic. 4 —Aspidiotus juglans-regie var. albus, A. crawii, and second lobes are very 
unequal, the inner being 
very large and curved, the outer very small. The second lobe is quite 
distinct; Mr. Johnson figures it as entire, but it is almost always 
deeply notched. 
A. ostreeformis (fig. 5), which has been found at Alameda, Cal., has 
the first and second lobes quite wide apart; but the second lobe, though 
small, is distinet. The form of the median lobes is somewhat peculiar. 
A. juglans-regie (fig.3) and its var. albus (fig.4) ought not to be 
confounded with perniciosus on account of large scale, but figures are 
given in case of any difficulty. The difference in the shape of the 
median lobes shown in the two figures is not a constant one, as between 
the type and variety. This species will be further known by the very 
well-developed rows of oval dorsal glands, which are extremely con- 
spicuous in mounted specimens. 
A. jv slane- Tan 
Vealbar. On ptar. Mtiilla 
A. andromelas (original). 
