54 THE SAX JOSE OB CHINESE SCALE. 
side is a small spine, and two or three such spines are just back of the 
second lobe, while back of these are three stout teeth curving- anteri- 
orly. A still smaller blunt tooth sometimes occurs near the middle of 
the lateral margin. The segmentation of the body at this stage is 
quite distinct. 
Mature female. — After reaching maturity the embryonic young are 
at first not visible, but later the body becomes filled with them. The 
mature female measures O.S mm wide by about l" 1 " 1 long." 
The following- description of this stage is reproduced from Comstock: 
The body of the female is yellowish and almost circular in outline: the segmenta- 
tion is distinct, tho not conspicuous. The last segment presents the followiug 
characters: 
There are only two pairs of lobes visible; the first pair converge at tip. are notched 
about midway their length on the lateral margin, ami often hear a slight notch < n 
the mesal margin, near the tip. The second pair are notched once on the lateral 
margin. 
The margin of the ventral surface of the segment is deeply incised twice on each 
side of the meson, once between the bases of the first and second lobes, and again 
laterad of the second lobe. On each side of each of these incisions is a club-shaped 
thickening of the body wall. 
There are two inconspicuous simple plates between the median lobes, and on each 
side similar plates extending caudad of the first incision, three small plates serrate 
on their lateral margin caudad of the second incision, and the club-shaped thicken- 
ings of the body wall hounding it, and three wide prolongations of the margin 
between the third and fourth spines. These prolongations are usually fringed on 
their distal margins. There are also, in some, irregular prolongations of the margin 
between the fourth spine and the penultimate segment. 
The first ami second spines are situated laterad of the first and second lobes, 
respectively: the third spine laterad of second incision, and the fourth spine about 
one-half the distance from the first lobe to the penultimate segment. 
SYSTEMATIC POSITION AND RELATIONSHIPS. 
The San Jose scale was described by Professor Comstock from 
material collected in 1SS0 in Santa Clara County. Cab. on apple, pear, 
plum, and other fruit trees. h The relationships of this scab 1 insect 
have been discust by various authors, notably by Prof. T. D. A. Cock- 
erell, without, however, reaching a very good solution, in the judg- 
ment of the writer. Without going into a detailed technical discus- 
sion, the San Jose scab 1 is quite as closely allied in structure, scale 
covering, and habit with the Aonidiella group as it is with the group 
including ancylus and ostreaeformis. It is a very distinct and well- 
marked species, however, and is always easy of identification after one 
becomes once familiar with its principal characteristic structural fea- 
tures, and it is one of the few scale insects which can ordinarily be 
" Rept. U. S. Dept. Agric, L880, p. 304. 
bReporl of the Entomologist, in the Report of Commissioner of Agriculture for 
1880 (1881), pp. 304, 305. 
