2 The Irish Naturalist, January 



at Kingstown. On this authority it was induded in M'Nab's 

 hst ^ and again in the 1901 Hst where, however, an 

 additional record is given — " River Dodder at Oldtown," 

 for a specimen taken by H. K. Gore Cuthbert and apparently 

 named by G. A. Lewcock. I have unfortunately failed to 

 discover any trace of either Hogan's specimen or that 

 found by Cuthbert. The latter specimen apparently passed 

 into Lewcock's hand and his collections, I learn from Mr. 

 Newbery, were sold some years ago, the water-beetles 

 apparently having been purchased by a collector on the 

 Continent. 



The only other Irish record for the species is one by 

 Donisthorpe, who, in 1905 reported it from Wicklow ^. At 

 my request he courteously sent me all his specimens, and 

 they turn out to be a rather dark form of /. aenescens, 

 Thoms. Fowler, in " British Coleoptera," 1887, separates 

 these two species by several characters but rather em- 

 phasizes the difference in colour. He says of the former 

 " upper surface deep black without trace of bronze re- 

 flection," while the latter is described as having '' a distinct 

 aeneous reflection," Now this colour separation is not 

 reliable. So far as I know, guttiger is always black but 

 aenescens varies greatly in the quality of the aeneous re- 

 flection. Those from Kippure, where Donisthorpe collected, 

 are mostly very black, although brassy-coloured ones occur ; 

 and when I collected on the same grounds last March, I 

 thought at the time that I was taking both species. There 

 are, however, certain characters upon which these two 

 species can easily be separated. One, applicable to both 

 sexes, is the appearance of the groove in the mesosternum 

 which receives the prosternal process. In aenescens this is 

 shallow and appears rather short, while in guttiger it is 

 deeper and appears longer. There are also other characters 

 for separating the males of these species besides those given 

 by Fowler and other authors. The claws of the anterior 

 tarsi viewed from below are quite distinct in the two species. 



1 British Association Guide, Dublin, 1878. 



2 Coleoptera in 1905. Ent. Rec, xvii., 1905, p. 291. 



