332 On Aquatic Carnivorous Coleoptera or DytiscidcB. 



Museum ; it was obtained from Chevrolat's collection, and is I believe an authentic 

 individual received from Motschoulsky : a second specimen associated with it in 

 Chevrolat's collection is a female of H. confertus. Hydrovatus obtusus much 

 resembles H. confertus, (No. 202), but is narrower and more parallel, considerably 

 less acuminate behind, and has the surfiice less densely and distinctly punctured ; it is 

 also peculiar in form, the narrowing of the elytra commences nearer the apex than 

 in the allied species, so that the form is broader and more truncate behind. 



India. IG. 



211. Hydrovatus politus, n. sp. — Ferrugineus, nitidus, convexus, prothorace 

 crebre subobsolete punctato ; elytris obsolete punctatis, seriebus punctorum sat 

 distinctis, coxis fere impunctatis. Long. Zl, lat. 2l m.m. 



Clypeus almost without margin ; antennre slender and rather short. Thorax with 

 numerous but indistinct punctures. Elytra with the punctuation very obsolete, 

 except that each bears some moderately evident traces of series of longitudinal 

 punctures, one of these series, along the suture, is only distinct towards the apex ; 

 the second series is the most distinct, while the third and fourth are very indistinct. 

 The hind coxae are almost impunctate, and the hind trochanters rather close to one 

 another. 



This .species is very closely allied to H. castaneus, Motsoh. (No. 217), but is 

 rather broader, and a little more acuminate behind ; the sculpture of the surface is 

 more obsolete, but the sutural series of punctures is more distinct, and the antennae 

 are rather shorter. 



Aiistralia, (Port Bowen). 11. 



212. Hydrovatus nigricans, n. sp, — Nigro-piceus, nitidus, convexus, latus, dense 

 fortiter punctatus, antennis pedibusque rufis ; trochanteribus posterioribus valde 

 distantibus. Long. 4|, lat. 2| m.m. 



Antennae rather long, and slender. Thorax closely and distinctly punctured. 

 Elytra rather coarsely and closely punctured, and with rudiments of one or two 

 longitudinal series of punctures. Coxce rather closely but irregularly punctured. 

 Middle and hind legs very widely separated. 



The only difference I see between the sexes of this species is that in the male the 

 basal joints of the front and middle tarsi are broadly dilated. 



Madagascar. 19. 



213. Hyphydrus uniformis, Fairm. Ann. Soc. Fr. 1869, p. 185. — Nigro-piceus, 

 subopacus, latus, subrotundatus, convexus, dense fortiter punctatus, antennis pedibus- 

 que rufis, illis crassiusculis. Long. 41 m.m., lat. 3 m.m. 



