410 On Aquatic Carnivorous Coleoptera or Dytiscidce. 



I. 37.— Genus ANTIPORUS. 



Posterior portion of epipleura comparatively broad ; hind tibia punctured on the 

 inf'ero-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 fequaliter, sat subtiliter punctatus, subopacus, niger, prothorace utrinque, 

 pedibus antennisque rufo-testaceis, his versus apicem infuscatis, elytris versus 

 latera signaturis obsolete rufescentibus ; corpora subtus densissime fequaliter 

 2)unctulato, opaco. Long. 5, lat. 2f, 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 tibia3 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 vai-iety 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 fusgo-niger, signaturis magnis testaceis ornatus ; corpore subtus 

 densissime fequaliter punctulato, opaco. Long. 43, lat. 2^ m.m. 



This species is closely allied to Hydroporus femoralis (No. 428), but is narrower, 

 and is more oi'namented 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 sequaliter sat fortiter punctatus, subopacus, niger, supra 



* In addition to them, the following should be refen-ed to the genus : Hydroporus gravidus, Clk. (No. 

 1374 huj. op.) near No. 434 ; Australia. 



