On Aquatic Carnivorous Coleoptera or Dytiscide. 363 
gracilibus, tibiis anterioribus sat latis; tarsis anterioribus et intermediis fortiter 
dilatatis tarsis posterioribus gracilibus. Long. 3, lat. vix 13 m.m. 
 Oblongo-ovalis, sericeo-subopaca, rufescens, elytris pectoreque obscurioribus ; 
elytris basi sparsim apice crebre punctatis ; antennis brevioribus, crassiusculis, tibiis 
anterioribus latis, tarsis posterioribus crassiusculis. Long. 22 m.m. 
The sexes of this species have the appearance of being quite distinct species. 
Australia, (King George’s Sound, Swan River.) 89. 
304. Bidessus dispar, n. sp.—Oblongo-ovalis, brevis, obscure castaneus, elytris 
crebre punctatis, tibiis anterioribus et tarsis posterioribus sat gracilibus. Long. 24, 
lat. 1 m.m. 
Mas, nitidulus, elytris sat fortiter punctatis, antennis gracilibus, tarsis anterioribus 
et intermediis leviter dilatatis. 
Fem., (a.) subopaca elytris subtiliter punctatis, antennis crassis. 
(b.) opaca elytris obsolete punctatis, antennis crassis. 
In this species there exists two forms of the female and the sexual characters 
are very remarkable ; besides those mentioned above, the hind legs of the male are 
a little longer and more slender than those of the female. 
Australia, (Swan River). 90. 
305. Bidessus occultus, n. sp.—Sub-oblongus, parum elongatus, castaneo- 
testaceus, capite obscuriore ; elytris crebre subtiliter punctatis ; coxis posterioribus 
parce subtiliter punctatis. Long. 13, lat. 1 m.m. 
This little species differs from Hydroporus lacustris (No. 319), by its smaller size 
more strongly punctured elytra and paler under surface. It is still closer to some of 
the smallest varieties of Hydroporas affinis (No. 318), but it is still smaller, and is 
of different form, its upper surface being flatter, and the outline much less acuminate 
behind and the wing-cases are without paler markings. I have seen only a single 
individual. 
Arabia, (El Hedjaz. Dr. C. Millingen). 1128. 
306. Bidessus perforatus, n. sp.—Clypeo antice incrassato, sed vix marginato ; 
oblongo-ovalis, brevis, rufo-testaceus, elytris sordide testaceis obsoleteque parce 
fusco-adspersis, fortiter sat crebre punctatis, fere nudis; coxis posterioribus abdom- 
Inisque segmentis basalibus utrinque fortiter punctatis. Long. vix 2, lat. 1 m.m. 
The only two specimens I have seen of this distinct little species, have the front 
and middle tarsi very slender, and are probably females. The prosternal process is 
strongly margined at the sides. 
China, (Kiu Kiang, Mr. Geo. Lewis). 106. 
TRANS. ROY. DUB. SOC., N.S., VOL. II. 3B 
