262 On Aquatic Carnworous Coleoptera or Dytiscide. 
ante-apicali pallidioribus, seriebus 5 vel 6 punctorum impressorum minus regulari- 
bus; corpore subtus impunctato; antennis brevibus, simplicibus, articulis haud 
transversis. Long. 23, lat. 13 m.m. 
I can see no sexual differences among the few individuals at my disposal; the 
pale marks on the elytra are ill-defined, and sometimes scarcely to be distinguished. 
Australia, (Rockhampton), 464. 
9. Hydroporus rubescens, Clk. M.C.—Oblongo-ovalis, transversim sat convexus, 
nitidus, testaceus, elytrisseriebus subregularibus punctorum impressorum minutorum ; 
corpore subtus impunctato ; antennis brevibus, articulis 4—10 leviter transversis. 
Long. 2, lat. 1 m.m, 
I see no sexual differences among the small series I have examined: 
It is possibly the insect Motschulsky intended to name Hydrocoptus rufulus, 
Etudes Ent. 1859 p. 44, 
Siam, (Bangkok, Castlenau) ; Java (fide Clark). 465, 
10. Hydrocoptus vittatus, n. sp.—Oblongo-ovalis, transversim minus convexus, 
nitidus, testaceus; elytris fuscis, vitta indeterminata marginalialiaque juxta-suturali 
abbreviata pallidis, seriebus obsoletissimis punctorum impressorum; corpore 
subtus impunctato; antennis brevibus, articulis;4—10 leviter transversis. Long. 2, 
lat. 1 m.m. 
Though apparently very closely allied to Hydroporus rubescens (No. 9), this 
species is very easily distinguished by the colour of the elytra. 
Northern India, (Boyd) ; Sarawak, (Marquis Doria). 466. 
The individual from Sarawak differs slightly from the type from Northern India : it has the punctures 
of the elytra scarcely so fine, and the antenne not quite so short. 
11. Hydrocoptus seriatus, n, sp.—Oblongo-ovalis, transversim sat convexus, 
pernitidus, testaceus, elytris castaneis, seriebus punctorum impressorum conspicuis ; 
corpore subtus impunctato ; antennis brevibus, articulis haud transversis. Long. 
22 m.m. 
The larger size and the much more conspicuous series of punctures on the elytra 
readily distinguish this from the preceding species Hydrocoptus vittatus (No. 10) ; 
it is much smaller than Hydrocoptus bivittis and has the series of punctures more 
regular and distinct. 
Madagascar, (Wehncke). 608. 
12. Hydrocoptus bivittis, Motsch. Hydroporus biwvittis, M.C._—Oblongo-ovalis, 
