BvUish Species of Haliplus. 



109 



ill tlie different species, but there is occasionally a small tuft 

 of a few stiff hairs at or near the apex. This lobe is plenti- 

 fully supplied with muscles, which run into it at right angles 

 to its base. 



The other lobe varies greatly in shape, being quadrilateral 

 in some species and triangular in others, but even in the 

 quadrihitcral-shaped ones the base is always broader than 

 the opposite side and the shape is rather that of a triangle 

 of which one side has a slight bend in it. One of the basal 

 angles of this lobe is greater than a right-angle, while the 

 other is acute, and at this latter the lobe is attached to the 

 base of the ajdeagus. The side of the lobe running up from 

 the angle of attachment is usually somewhat excised, and is 

 always, so far as I know, fringed for at least part of its length 

 with stiff hairs. At the extremity of the lobe there is usually 

 a tuft of stiff hairs, which Edwards described as a " long- 

 curved spine " (5, p. 2). 



Firr. 2. 



Dlagranimatic sketch of fedeagus, witli the " tongue" {>)) moved out of 

 position, to show the depress-ion {b') in whicli it lies, and also to 

 show the opening of the ductus ejaculatorius (/). rt = maiu lobe; 

 c=the " hood " ; c?=the saccular region, with its " wing " {d') ; e = 

 the thin wall of the ductus; r/=the groove in the "tongue," with 

 the continuing groove on the main lobe (^'). 



The ajdeagus itself (see fig. 2) is a peculiar structure, its 

 chief peculiarity lying in the fact that it is asymmetrical. It is 

 a strongly curved chitinous organ into which passes the ductus 

 ejaculatorius, but this tube opens about halfway back along 

 the organ upon what is really its left side, the opening being 



