312 DR. A. E. SHIPLEY ON [ Mar. 16, 
The body is, on the whole, flattened—especially is this the case 
with the head and abdomen. The thorax, as Snodgrass* points 
out in Menopon persignatum, appears to be triangular in cross- 
section. 
The Head.—The head is shaped somewhat like the semicircular 
knives used for cutting cheese. The head of the female is some- 
what broader and shorter than that of the male, and is produced 
at the posterior-lateral region into a much more prominent angle. 
In both male and female the angle bears a spine and a long hair. 
The anterior rim of the head is bounded by a thick rim of chitin, 
beneath which is a layer of granular protoplasm with a few nuclei, 
the hypodermis. At intervals the chitin is pierced by narrow 
channels, into which the hypodermis extends, and the chitin bears 
at the outer end of each of these channels a short hair (Pl. XXXVI. 
fig. 4). From the inner surface of this rounded anterior edge 
of the head a number of muscle-fibres pass radially inwards to a 
structure which has been called the upper lip, and which will be 
described later under this name. Just in front of the recess 
from which the antenne arise, the anterior thickened chitinous 
rim curves to an end, being bent in and then out to form a short 
apodeme of which the inner end acts as the basis of articulation of 
the anterior limb of the stout mandibles(Pls. XXX VI.& XXX VII. 
figs. 4 & 6). The socket of the antenne is also provided with a 
thickened chitinous skeleton, and across the base of the head, 
separating it from the prothorax, is a thickened plate which 
presents in profile the appearance of a bow; the rest of the head 
is enclosed in thin yellow chitin. The appendages of the head 
will be described later, together with those of the body. 
There is no neck, but the first segment of the prothorax is 
only about one-half the width of the head. The mesonotum 
is fused with the metanotum and the thorax appears to have but 
two segments. There is, again, no waist or constriction between 
the thorax and the abdomen, but the segments from the first 
thoracic to the second or third abdominal gradually and uniformly 
widen, and then as uniformly diminish in width until the last. 
The separation of the first thoracic segment from the second is 
marked by a stout chitinous rim both dorsally and ventrally— 
this is, however, only found in this region; the rest of the 
segments are soft and not chitinized in the tergal and sternal 
regions, but the pleura are protected by well-marked chitinous 
shields, which, however, extend but a very short way dorsally and 
ventrally (Pl. XXXYV. figs. 1,2 & 3). In Virmus, however, the 
lateral plates are more extended. 
According to Sharp? the Mallophaga have from 8 to 9 
abdominal segments, and according to Railliet £ the family in 
which he places Goniodes has 9; but he remarks that the last 
* Pap. Calif. Ac. vi. 1899, p. 146. 
+ Cambridge Natural History, vol. v. Insects, i. London, 1895. 
t ‘Traité de Zoologie Médicale et Agricole.’ 2nd Edn., Paris, 1895. 
