410 On Aquatic Carnivorous Coleoptera or Dytiscide. 
I. 37.—Genus ANTIPORUS. 
Posterior portion of epipleura comparatively broad; hind tibia punctured on the 
infero-external aspect; the true fourth joint of front tarsus is scarcely visible. The 
mesosternal fork is not connected with the intercoxal process of the metasternum. 
The eight species * are found in Australia, Tasmania and New Zealand. 
428. Hydroporus femoralis, Boh., M.C.—Ovalis, latiusculus, brevissime pubescens, 
dense zequaliter, sat subtiliter punctatus, subopacus, niger, prothorace utrinque, 
pedibus antennisque rufo-testaceis, his versus apicem infuscatis, elytris versus 
latera signaturis obsolete rufescentibus; corpore subtus densissime eequaliter 
punctulato, opaco. Long. 5, lat. 27, m.m. 
In the male the front and middle tarsi are broader than in the female, and the 
front ones bear only one claw, which is moderately long and bears a tooth at its 
extreme base; the middle tibiz are slightly curved; the hind femora have a large 
angular dilatation near the apex, on the outer side the sinus of this tooth is not 
angulated. In the female the elytra are sinuate-truncate at the apex. 
Although Boheman describes his H. femoralis as having the abdomen yellow, I 
believe it will prove to be a variety of this species. 
Tasmania, Australia. 422. 
429. Hydroporus interrogationis, Clk., M.C.—Ovalis, brevissime pubescens, 
dense sequaliter sat subtiliter punctatus, subopacus, niger, antennis pedibusque 
testaceis, supra fusco-niger, signaturis magnis testaceis ornatus ; corpore subtus 
densissime eequaliter punctulato, opaco. Long. 43, lat. 22 m.m. 
This species is closely allied to Hydroporus femoralis (No. 428), but is narrower, 
and is more ornamented with yellow, and the male characters show some slight 
differences ; the unguiculus of the anterior tarsus, is more thickened in the middle ; 
and the large dilatation of the hind femora takes the form of a tooth in consequence 
of its sinus externally being angulated. The female has the front tarsi more 
slender. All these characters vary somewhat in the small series of the two forms 
before me, and I fancy both may prove to be but one species. 
Australia. 423. 
430. Hydroporus wakefieldi, Sharp, Ent. Mo. Mag. XIII, p. 20.—Oblongo- 
ovalis, vix pubescens, dense equaliter sat fortiter punctatus, subopacus, niger, supra 
* In addition to them, the following should be referred to the genus: Hydroporus gravidus, Clk. (No. 
1374 huj. op.) near No. 434; Australia. 
