﻿1869.] 81 



NOTES ON BRITISH HYDRADEPHAGA ; WITH DESCRIPTIONS OF 

 NEW SrECTES OF HALIPLUS AND HYDROPORUS. 



BY DAVID SHARP, M.B. 



Having recently made a careful examination of the British 

 Hydradephaga, I publish the following descriptions and notes in order 

 to assist the Coleopterists of this country in giving names to certain 

 species hitherto undetermined in their collections. 



Haliplus striatus, n. s. 



Rufo-ferrugineus ; protTiorace vage punctilio, basi utrinque impresso ; 

 elytris subtiliter striato-punctatis, striis cequaliter fusco-lineatis. 



Long. 1^-line. 



Equal in size to the small varieties of H. ruficollis, which it resembles in 

 colour, but from which it may be distinguished by being much narrower at the 

 shoulders, and by the black lines on the elytra showing no tendency to being 

 dilated at any places into spots : also closely allied to H. fiuviatilis, but to be 

 distinguished from that species by its smaller size and darker colour, and by the 

 black lines on the elytra being throughout of even width, whereas in fiuviatilis 

 these lines are sub-interrupted at places. 



Found in great numbers in a pond a few miles from Dumfries, in 

 company with S. ruficollis, and also in other localities near that town. 



Obs. — I take this opportunity to remark that, in my opinion, 

 H. fiuviatilis and ruficollis are but races of one species, and that, if 

 this view be adopted, 3.. striatus may be considered as a third race. 

 If, however, H. fiuviatilis be considered as a distinct species from H. 

 ruficollis, it will be necessary also to keep H. striatus separate. Indeed, 

 though H. fiuviatilis and ruficollis are so variable that I have some 

 specimens which appear to me completely intermediate, H. striatus 

 appears to be very constant, and I have no difficulty in distinguishing 

 it from any of my vars. of either of the two other insects. 



Hydroporus obsolettts, Aube (Icon., &c, v. 298). 



This rare and distinct Hydroporus can be only compared with H. ferrugineus, 

 Steph. (victor, Aube.) ; it is readily distinguished from that species by its narrower 

 form, less variegated elytra, the quite impunctate disc of its prothorax, and its 

 more sparingly but more distinctly punctured elytra ; on each side of the thorax at 

 the base is an impression in which the punctuation is coarse, and close. 



Single specimens have occurred in several parts of the North of 

 England, and South of Scotland, to different Entomologists ; Mr. Bold, 

 Mr. Crotch, Mr. Lennon, and myself, It was distinguished from 

 ferrugineus some years ago by Mr. Eye, to whom a specimen taken 



