568 On Aquatic Carnivorous Coleoptera or Dytiscide. 
The male has the front and middle tarsi dilated, and the claws of the front feet 
nearly simple: there is no evident difference in the sculpture of the sexes. 
I have separated this from the numerous forms I have considered as being C. 
nigritulus, chiefly on account of the less dilated male tarsi, and the simple front 
claws. 
Australia, (Melbourne). 672. 
820. Copelatus subjectus, n. sp.—Ovalis, sat angustus et elongatus, subde- 
pressus, nigricans, elytris piceis, prothoracis lateribus elytrorumque basi dilutioribus, 
antennis pedibusque rufis ; capite crebre subtilius punctulato ; prothorace subleevi ; 
elytris seriebus punctorum tribus vel quatuor distinctis. Long. 6, lat. vix 3 m.m. 
In this species there are on the elytra two very distinct series of punctures, and 
between them is another series less distinct because the punctures composing it 
are much fewer in number, 7.e. placed at a greater distance from one another ; there 
is also a more external series which is less regular and distinct. I have seen only 
two individuals of this species, and suspect they are males, though the tarsi are 
scarcely perceptibly thickened. 
New Caledonia. 673. 
$21. Colymbetes parvulus, Boisd., Agabus parvulus, J1.C.—Oblongo.ovalis, haud 
elongatus, sat depressus, subopacus, fusco-rufus, anterius dilutior, antennis pedi- 
busque testaceis ; elytris seriebus punctorum obsoletis. Long. 42, lat. 25 m.m. 
This little species has the upper surface less shining than usual, owing to its being 
very finely reticulate or coriaceous; other sculpture is nearly absent. The sexes 
are difficult to distinguish, there being only a slightly greater development of the 
front and middle tarsi in the mate. 
Hawaiian Islands. 674. 
822, Copelatus politus, n. sp.—Oblongo-ovalis, depressus, pernitidus, fere leevis, 
piceus, supra magis nigricans, antennis ped:busque rufis ; fere leevigatus. Long. 4, 
lat. 2 m.m. 
The male has the front and middle tarsi very little dilated, but the intermediate 
joints of the antennee are broad and flattened, the third joint very strongly so, and 
the three following ones to a gradually diminished extent. 
New Guinea, (Hatam, July, 1875, Dr. Beccari), 660. 
823. Copelatus insolitus, Chev., M.C.—Oblongus, sat angustus, subdepressus, 
nitidus, testaceus, prothorace medio late infuscato, elytris fusco-testaceis basi 
