128 
or extension of a sack-like organ (d), shown exerted in Fig. 12, that is the 
instrument for the emission in a mistlike form of the particular substance alluded 
to. The latter act, though it is generally performed spontaneously, is also” 
prompted by the attention of ants that—at least, in Lecanium—seem to excite 
the insect by touching certain appendages or cerci, shown in Fig. 12, with 
which the excretory organ is endowed. f ) 
Although the foregoing remarks may be deemed sufficiently extended to 
throw some light on a subject that to most people is somewhat involved in 
obscurity, it must be borne in mind that there are several other equally 
interesting phases in the life history of Scale Insects that necessities of space 
forbid being entered into upon this occasion. 
DESCRIPTION OF PLATES. 
PLATE I. 
(Wote.—Euch object—except where otherwise stated—is represented with its length and breadth 
increased 12 times.) 
Fic. 1.—Purple Round Scale—A spidiotus Jjicus, Comstock : Female Scale. 1a, Male Scale. 
Fig. 2.—Red Scale—A spidiotus aurantii, Maskell: Female Scale; 2a, same as seen from{beneath 
Ae ie ventral Scale, (b) eggs occurring between ventral and dorsal Scales; 2)» 
Tale Scale. 
Fic. 3.—Rose Diaspis—Diuspis rose, Sandberg: Female Scale; 3a, Male Scale. 
Fic. 4.—Peach Diaspis—Diaspis amygdali, Tryon: Female Scale, smooth form; 4), Female 
Scale, hairy form; 4c, Male Scale, enlarged. (After H, HE, Green.) 
Fic. 5.—Parlatoria Scale. 
Fic. 6.—Glover’s Mussel Scale—Mytilaspis Gloveri, Comstock : Female Scale ; 6a, same, as seem 
from beneath. 
Fic. 7.—Fulvous Orange Mytilaspis—Mytilaspisfulva, Targioni-Tozzetti* : Female Scale; 1@, 
same, as seen from beneath, showing—(a) ventral scale, and (b) eggs. 7b,{Male Scale, 
both dorsal and ventral views. 
Fig. 8.—Apple Mytilaspis—Mytilaspis pomorum, Bouche : Female Scale. 8a, same as seen from 
beneath, showing—(q) ventral scale, (b) eggs. 
Fic. 9.—White Orange Scale—Chionaspis citri, Comstock: Female Scale. 8a, Male Scale. 
PLATE II. 
Fic. aes Soft Scale—ZLecanium longulum, Douglas: Female Scale; diameter magnified 
times, 
Fig. 2.—Soft Scale—Lecanium hesperidum, Linné : Female Scale. 
Fic. 3.—Soft Scale—Lecanium depressum ?: Female Scale. 
Fia. 4.—Olive Soft Scale—Lecanium olee, Bernard: Female Scale, showing characteristic ridge } 
mature, but not elevated as when filled with its progeny. 
Fic. 5.—Pink Wax Scale—Ceroplastes ruber, Maskell : Female Scale ; from specimen of medium 
size, showing (a) respiratory clefts in covering above spiracles. 
Fic. 6.—Sida Pulvinaria—Pulvinaria, sp.: Female Scale, showing (a) egg-sack; diameter 
magnified 6 times. 
Fic. 7.—Cottony Cushion Seale—Icerya Purchasi, Maskell: Female Scale, showing (a) egg-sack} 
diameter magnified 6 times. 
Fic. 8.—Mealy Bug—Dactylopius adonidum, Linn. : Female Scale. 
a a TE A SY 2 SO eee 
* This insect is usually named in Australia Mytilaspis citricola, Packard. But the characters assigned by 
Packard (“ Guide to the Study of Insects, 1870,” pg. 527) for his Aspidio/us citricola are so meagre as to be ine 
sufficient to distinguish his species from Mylilaspis pomorum, B.—x Scale Insect also occurring upon citraceous 
trees, The writer therefore adopts the name under which the first recognisable description was publis 
and in doing so follows A, Berlese and other authors. 
