81 
»TES ON BRITISH HYDRADEPHAQA ; WITH DESCRIPTIONS OF 
NEW SPECIES OF HALIPLU8 AND HYDBOPORUS. 
BY DAVID SlIABP, M.B. 
laving recently made a careful examination of the British 
adepJiaga,! ]yuh\ish the following descriptions and notes in order 
dst the Coleopterists of this country in giving names to certain 
es hitherto undetermined in their collections. 
[PLUS STRIATUS, H. iS. 
Rufo.ferragineus ; protlwrace vage punctata, hasi utrinque inipresso ; 
is subtiliter strlato-punctatis, striis aqualiter fusco-Uneatis. 
Long, li-liue. 
Squal in size to the small varieties of H. rujicollis, which it resembles in 
r but from which it maybe distinguished by being much narrower at the 
ders and by the black lines on the elytra showing no tendency to bemg 
,d at any places into spots: also closely allied to E. fiwrnoMhis, but to be 
iguished fi-om that species by its smaller size and darker colour, and by the 
: lines on the elytra being throughout of even width, whereas in fiuv^aUl^s 
I lines are sub-interrupted at places. 
Found in great numbers in a pond a few miles from Dumfries, in 
pany with R. ruficoUis, and also in other localities near that town. 
Obs.— I take this opportunity to remark that, in my opinion, 
fluviafilis and ruficollis are but races of one species, and that, if 
view be adopted, R. striatus may be considered as a thn-d race, 
lowever, R. fluviatilis be considered as a distinct species from R. 
collis, it will be necessary also to keep R. striatus separate. Indeed, 
ugh R. fluviatilis and ruficollis are so variable that I have some 
cimens which appear to me completely intermediate, R. striatus 
,ears to be very constant, and I have no difficulty in distinguishmg 
i-om any of my vars. of either of the two other insects. 
:droporus obsoletus, Aube (Icon., &c , v. 298). 
This rare and distinct Eydro^orus can be only compared with H. ferruginetis, 
ph {victor, Aub6.) ; it is readily distinguished from that species by its nai-rower 
tn less variegated elytra, the quite impunctate disc of its prothorax, and ,ts 
re' sparingly but more distinctly punctured elytra; on each side of the thorax at 
, base is an impression in which the punctuation is coarse, and close. 
Single specimens have occurred in several parts of the North of 
igland, and South of Scotland, to different Entomologists ; Mr. Bold, 
r. Crotch, Mr. Lennon, and myself, It was distinguished from 
rrngimus some years ago by Mr. Rye, to whom a specimen taken 
