802 
Sfi((lie.s on Fedicidus 
0-4-0-7 mni. transversely, is studded over with short chitinous tuberosities 
or teeth that point outwardly and basally; some areas, as shown in this 
and succeeding figures, appear finely granular and devoid of teeth. 
Protruding from the left side of the vesica, and this position appears 
to be constant, there is a darkly chitinized tubular structure, the penis 
{Pen.). The latter is continuous basally with the walls of the vesica 
and with a peculiarly shaped rod {St. pen.) imbedded in the wall of the 
sack. 
When viewed laterally, as shown in the semi-schematic Text-fig. 2, 
the relations of some of the chitinous structures enumerated will be more 
Fig. 1. Pediculus hiimnnus cJ. Extruded copiilatory apparatus seen from behind in a 
male forcibly removed from a female whilst in copula and promptly killed. 
clearly understood; they are represented in solid black. The sack or 
vesica is represented by a serrated contour denoting the teeth which 
project from its surface, it issues from a cleft in the dilator {Dil.), the 
cleft being, however, better seen in subsequent figures. The teeth on 
the surface of the vesica are omitted for clearness’ sake, the statumen 
penis {St. pen.) and penis {Pen.) are represented in black. The structure 
of the dilator will be best understood by reference to Plate III, figs. 
1 and 2, wherein it is shown as it appears when retracted within the body 
of the male (fig. 1) and when extruded (fig. 2). The dilator is sharply 
