66 INSECTS NOXIOUS TO AGRICULTURE. 
The antennee of the adult female have six or seven joints. 
It is often very difficult to determine the number, as the third 
joint exhibits frequently a shallow circular depression or ring 
which may easily be mistaken for a division. 
During gestation the female, which at first fills the test, 
shrivels up at one end into a shapeless mass requiring macera- 
tion in potash to restore the original form for examination. 
The test thus becomes almost filled with eggs. 
The presence of the fringe, which is noticeable in every 
species of this genus at some time or other, distinguishes it from 
Ceroplastes and Vinsonia. In Ctenochiton viridis the test is not 
to be made out in the adult stage but is clearly visible in the 
second stage of the female, and it is present, with the charac- 
teristic fringe, for the male. 
31. CrenocHIToN pEPREssUs, Maskell. 
N.Z. Trans., Vol. XVI., 1883, p. 132. 
(Plate VIL., Fig. 2.) 
Test of adult female flat, nearly circular, thin, waxy, greyish- 
coloured ; frimge inconspicuous or sometimes absent. No per- 
forations or rows of air-cells. Diameter, about 4in. 
The fringe is more conspicuous in the test of the second 
stage. 
Test of male elongated, narrow, flat beneath, slightly convex 
above, white, glassy, thin and brittle, with a conspicuous frmge 
of which the segments are truncato-triangular. The test is 
divided into tessellations, the median row of which is quadran- 
gular, with two series of pentagonal divisions between it and the 
fringe. Near the abdominal extremity a transverse narrow slit 
cuts the test in two, leaving a small segment at the extreme end 
apparently separate. Length of the test about yin. 
Adult female filling the test, but shrivelling after gestation ; 
colour brownish or grey. Antennee of six joints, the third being 
the longest, and, as is commonly the case in the genus, often 
appearing like two. On the last jomt a few long hairs. Foot 
normal; the upper digitules are fine hairs, the lower pair only a 
little broader. Anal ring and lobes normal. 
In the second stage the usual wavy edge is conspicuous; the 
test is thin, glassy, with normal fringe. Antenne and feet 
normal. The insect is somewhat thick, with yellowish colour. 
