British /S^/)ec/Vs o/Haliplus. Ill 



and tlie two accessory lobes (parameres or periphallic lubes) 

 are alike, and the gedeaorus itself is deeply channelled along 

 its convex side, the " tongU'i " lying over this median 

 ciiannel. On the upperside of the tongue and along its 

 median line is a distinct ridge, and I imagine that, in the 

 asymmetrical flattening of the whole apparatus in the Hali- 

 ])iids, this ridge has become bent over so as to form the lip of 

 the groove wiiich runs along the outer face of this tongue. 



In a state of rest the tsdeagus with its accessory lobes lies 

 on its side within the last abdominal segments, the concavity 

 of the sedeagus being towards the left side of the insect, and 

 the scale-like lobe lies above the sedeagus and ^he other 

 below. It is difficult, except by comparison of the armature 

 with other and regular types, such as Hi/drophilus, to realize 

 tiie orientation of the parts, but by such comparison it be- 

 comes evident that the curvature of the aideagus has necessi- 

 tated its being varied from its normal position, and that, in a 

 state of rest, it lies upon its left side, the concave edge being 

 the true dorsal side of the organ. When protruded the whole 

 armature turns on its axis through an angle of 90°, so that 

 the dorsal side becomes ventral and the left accessory lobe 

 lies on the right side ; then, by the bending of the region 

 immediately behind the accessory lobes, the whole armature 

 is bent downwards and forwards, so that the dorsal side once 

 more becomes uppermost as it enters the vagina of the female. 



The Britannic Species. 



I. //. apicaUs, Thomson, is, I believe, identical with 

 H. striatus, Sharp. 



This species was first described in 18G7, and no mention 

 is made of it by Sharp in his description of striatus in 1869. 

 Presumably he did not know Thomson's species. In his 

 description Sharp remarks the resemblance between his 

 species and H.Jluviatilis, and points out tiiat if this latter 

 species is merely a variety of H. riijicollis, tlun H. striatus is 

 only another variety. No one had at that time worked at 

 tlie Iialiplid«, so that very little was known about them, 

 and it seems that many subsequent authois have had no 

 knowledge of Sharp^s species beyond his dt'scription of it, 

 and have accepted the suggestion that it may be a varietal 

 form. Ganglbauer (7), for instance, disregarding the work 

 of Gerhardt and Wehncke, includes not only striatus, but 

 also loelinckei and immaculatus, as varieties of ruJicolUs. 

 lieitter (15, p. 204:) describes striatus as an aberration of 



