118 Mr. F. Balfour-Biowne on the 



Hunts, Cambs, Norfolk E., Suffolk E. and W., Middlesex, 

 Surrey, Sussex E.^ and Kent E. and W. It also occurs iu 

 the Isle of Man. 



II. riificoUis is a typical pond-species and becomes rare in 

 peaty districts, so that it may well be absent from large 

 tracts of Scotland and Ireland. 



In the section dealing with the puncturation of the elytra 

 o£ the female, I mentioned that I had impunctate continental 

 specimens which I was unable to determine as between this 

 species and //. heydeni. These females are larger than British 

 heijdeni, and they seem rather broader and with rather more 

 deeply punctured elytra! stride than our riificolUs, and we are 

 therefore faced with the question whether there is another 

 species, H. multvj)unctatus^ VVehncke, to be recognized in this 

 group, and, as Sharp (20) believes that he has a British female 

 specimen of this species, it is necessary that I should thus refer 

 to it in this paper. I can only say that among the con- 

 tinental specin)ens in my possession 1 can find no male which 

 can be associated with these larger im))unctate females, except 

 that of riijicol/is, but I do not notice llnit these rvficoUis have 

 a less prominent gedeagal hood than our British specimens. 

 Personally, being what Darwin called a "whole-hogger" 

 rather than a " hair-splitter," I should hesitate to regard 

 so small a diflference as anything more than a varietal 

 distinction. 



General Summary of Characters. — 



[\. General form: elytra widest close beliind the shoulders and 

 narrowing rather strongly so that the aj^ex is rather acute. 



( 2. Thorax apparently more than twice as broad as long, the sides 

 . J curved and strongly convergent. 



"I 3. Thoracic strife variable ; perhaps most usually short and 



I straight, but not infrequently somewhat incurved, 



I 4. Elytra with the black lines almost always broken and spreading 



1^ out into patches of colour. 



1^1. Ant. tarsal claAvs unequal, both comparatively straight near 



I apex (cf. II. wehnckei). 



\ 2. Apical segment of ant. tarsus rather long (cf. H. wclmchei and 

 J.-<( immacitlatus). 



I 3. The tliree basal segments of ant. tarsi with dense pads of hairs 



I on under side (cf. H. welinckei). 



1^4. Basal segment of median tarsus not excised on posterior side. 



f 1, Elytra in most Britannic specimens with tine puncturation all 



I over. On the continent this form seems to be rare, tlie 



2 .-^ elytra usually varying from smooth in the ant. half to smooth 



I nearly all over. Some Britaimic specimens have elytra 



1^ smooth in ant. half. 



The sedeagus of this species is sufficiently described already, 

 as the diagrammatic figure and the accompanying descrip- 

 tion are founded upon it. 



