On Aquatic Carnivorous Coleoptera or Dyliscidce. 357 



283. Bidessus daemeli, (Wehncke), n. sp. — Oblongo-ovalis, sat elongatus, sub- 

 opacus, rufo-testaceus, prothorace basi medio nigro, elytris fusco-variegatis, dense 

 subtiliter punctatis, distincteque pubescentibus ; coxis posterioribus subtiliter ^ed 

 perspicue punctatis. Long. 2|, lat. It m.m. 



Mas, tarsis anterioribus et intermediis mediocriter dilatatis, abdomine 

 infuscato. 



Fern., tarsis simplicibus, abdomine riifo. 



Australia, (Cape York, Port Denison, Rockhampton). 94. 



284. Hydroporus mastersi, MacLeay, Tr. N. S. W. 1871, p. 123.— Oblongo- 

 ovalis, elongatus, subopacus, rufo-testaceus, thorace basi medio elytrisque nigro- 

 signatis, pectore abdoiuineque fuscis ; elytris dense subtiliter punctatis, coxis 

 posterioribus crebre fortiter punctatis. Long. 3, lat. IJ m.m. 



In the male the front tarsi are distinctly broader than in the female, and the 

 hind tarsi are slightly longer. 



Australia, (Gayndah, Rockhampton). 95. 



285. Bidessus orthogramraus, n. sp. — Oblongo-ovalis, elongatus, subopacus, rufo- 

 testaceus, thorace basi medio elytrisque nigro-signatis ; elytris dense subtiliter 

 punctatis, coxis posterioribus crebre sat fortiter punctatis. Long. 2f, lat. ll m.m. 



I have seen only a single female individual, and it is just possible it may not be 

 distinct from Hydroporus mastersi ; it is brighter in colour, and unicolorous beneath, 

 the markings on the elytra are less confused and more linear longitudinally, the 

 punctuation of the upper surface is a little more dense, and that of the hind coxae 

 not quite so coarse. 



North-west Australia. 96. 



286. Hydroporus japonicus. Sharp, Tr. Ent. Soc. Lond. 1873, p. 54. — Oblongo- 

 ovalis, supra rufo-testaceus, capite prothoracisque basi plus minusve infuscatis, 

 elytris sat crebre distincte punctulatis, signaturis longitudinalibus plus minusve 

 coalescentibus nigris ; subtus piceus, coxis posterioribus parce et subtiliter sed 

 distincte punctatis. Long. 2, lat. 1 m.m. 



Rather narrower and more parallel than Dytiscus geminus, (No. 269), more 

 brightly coloured, and with the punctuation of the upper surface more distinct, and 

 the sides of the thorax a little curved. 



The external sexual characters seem to consist only in a very slight dilatation of 

 the front and middle tarsi in the male. ■ 



This species varies a good deal in size and colour, and in the markings of the 



3 A3 



