On Aquatic Carnworous Coleoptera or Dytiscide. 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 sed 
perspicue punctatis. Long. 23, lat. 1¢ m.m. 
Mas, tarsis anterioribus et intermedius mediocriter dilatatis, abdomine 
infuscato. 
Fem., tarsis simplicibus, abdomine rufo. 
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 abdomineque fuscis ; elytris dense subtiliter punctatis, coxis 
posterioribus crebre fortiter punctatis, Long. 3, lat. 1} 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 orthogrammus, 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. 24, lat. 13 m.m. 
I have seen only a single female individual, and it isjust possible it may not be 
distinct from Hydroporus masters! ; itis 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 coxe 
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 
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