262 On Aquatic Carnivorous Coleoptera or Dytiscidce. 



ante-apicali pallidioribus, seriebus 5 vel 6 punctorum impressorum minus regulari- 

 bus ; corpore subtus impunctato ; antcnnis brevibus, simplicibus, articulis baud 

 trans versis. Long. 23, lat. Is m.m. 



I can see no sexual difterences 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,elytris seriebus subregularibus punctorum impressorum minutorum; 



corpore subtus impunctato ; antennis brevibus, articulis 4 — 10 leviter transversis. 



Long. 2, lat. 1 m.m. 



I see no sexual diflferences amonop the small series I have examined: 



It is possibly the insect Motschulsky intended to name Hydrocoptus rufulus. 



Etudes Ent. IS 59 p. 44. 



Siam, (Bangkok, Castlenau) ; Java (fide Clark). 465. 



10. Hydrocoptus vittatus, n. sp. — Oblongo-ovalis, transversim minus convexus, 

 nitidus, testaceus; elytris fuscis, vitta iudeterminata 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 antennae not quite so short. 



11. Hydrocoptus seriatus, n. sp. — Oblongo-ovalis, transversim sat convexus, 

 pernitidus, testaceus, elytris castaneis, seriebus punctorum impressorum cons|)icuis ; 

 corpore subtus impunctato ; antennis brevibus, articulis baud transversis. Long. 

 2\ m.m. 



The larger size and the much more consjiicuous series of punctures on the elytra 

 readily distinguish this from the preceding species Hydrocoptus vittatus (No. 1 0) ; 

 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 bivittis, M.C. — Oblongo-ovalis, 



