NEW BRITISH SPECIES, ETC., IN 1869. 47 



7. Hydroporus unistriatus, Schrank; Aiibe, 1. c, 498; 



Schaum, 1. c, 42; D. Sharp, Ent. Mo. Mag., vi, 85. 



A pair of this species, formerly in our lists, from which it 

 was removed, as having been incorrectly introduced, have 

 recently been taken by Mr. Crotch in Norfolk. 



Mr. Moncreaff informs me, that he took a single specimen 

 (named for him by Mr. Crotch) in brackish water at 

 Southsea, in the summer of 1868. 



It is intermediate in size between mimitissimus and gemi- 

 nus, to which it is allied, having the stria carried on from 

 the thorax to the elytra ; and is oval, pitchy, with testaceous 

 thorax, of which the anterior and posterior margins are 

 blackish, and the elytra dilated in the middle, confusedly 

 variegated with testaceous, and with a single abbreviated 

 sutural stria. 



It appears to be spread over the whole of the rriiddle of 

 Europe, but to be nowhere common, except, perhaps, in 

 France (according to Fairmaire). 



8. Hydroporus discretus, Fairmaire, Ann. de la Soc. 



Ent. de Fr., 1859, p. 28; Schaum, 1. c, 64; D. 



Sharp, 1. c, 82 ; W. R. M'Nab, ib., 87 ; T. J. Bold, 



ib., 161. 



nigrita, Sturm ; Thoms., Sk. Col., ii, 24. 



piibescens, Thoms., Sk. Col., ix, 79. 

 Dr. Sharp, noting that this species is mixed in our collec- 

 tions with what he considers (rightly, as I imagine) to be 

 •nigrita^ Fab. (= glahellus, Thomson, according to type from 

 that author), distinguishes it from that insect by its punc- 

 tuation and pubescence being very much less sparing, and 

 its upper surface being brighter and not finely and densely 

 coriaceous, as in nigrita. Thomson has increased the 

 original difficulties of identification bv " rinmnfr the changes" 

 between nigrita and pubescens, and applyins" in turn each 



