168 Haemaphysalts punctata 
variably attempts to remove itself as far as possible from a source of 
light if exposed. 
It must be borne in mind, especially in the reading of specific 
descriptions of Ixodoidea, that the general appearance undergoes very 
considerable transformations during and after engorgement; this is 
most noticeable in the larva, nymph and female, but the male may 
be considerably altered (see PI. XIII). In the matter of colour, the 
gorged female exhibits any colour from pale greyish-yellow to almost 
pitchy-black. Prolonged immersion in preservatives, especially in 
alcohol, may completely modify the original colour, gorged females 
of H. punctata usually acquiring a more or less uniform dark reddish- 
brown tint. 
I. The Capitulum of the Female. 
(Plate XIV, Figs. 1 and 2, Text Figs. 3—5.) 
The capitulum is the head-like structure, situated at the anterior 
extremity of the body, upon which is borne the oral opening with its 
accompanying appendages. The large basal portion, hereafter spoken of 
as the basis capituli (b.c.), is constricted in its posterior half and this neck- 
like portion is telescoped into the anterior opening of the body cavity. 
The anterior portion of the basis capituli is roughly rectangular in 
shape, with flattened surfaces dorsally and laterally, and somewhat 
convex ventrally. A pronounced salient ridge, the dorsal ridge (d.r.), 
runs transversely across the dorsal surface, which, when the capitulum 
is raised in a line with the body-axis, comes in contact with the anterior 
margin of the scutum, the posterior constricted portion being concealed 
beneath the latter. Ventrally, the anterior portion of the basis capituli 
is differentiated by another ridge, the ventral ridge (v.r.), running in a 
transverse direction and curved, with its convexity directed posteriorly 
but not so sharply raised as the dorsal ridge. The sides of the basis 
capituli are flattened and the dorsal and ventral ridges are not 
continuous. 
At the antero-lateral angles of the basis capituli, deeply implanted 
into a pair of large rectangular fenestrae, are the palps (p.). The ventral 
surface of the basis capituli is produced anteriorly in the median line as 
a spoon-shaped prolongation beneath the mouth; this structure is termed 
the hypostome (h.). On its dorsal side, the basis capituli is prolonged 
between the palps as a pair of parallel tubes which ensheath the 
chelicerae. The dorsal surface shows a pair of large shallow saucer-like 
