332 On Aquatic Carnivorous Coleoptera or Dytiscide. 
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 surface 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. 16. 
211. Hydrovatus politus, n. sp.—Ferrugineus, nitidus, convexus, prothorace 
crebre subobsolete punctato ; elytris obsolete punctatis, seriebus punctorum sat 
distinctis, coxis fere impunctatis. Long. 3%, lat. 24 m.m. 
Clypeus almost without margin ; antennz 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 coxe are almost impunctate, and the hind trochanters rather close to one 
another. 
‘This species is very closely allied to H. castaneus, Motsch. (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 antennze 
are rather shorter. 
Australia, (Port Bowen). 11. 
212. Hydrovatus nigricans, n. sp.—Nigro-piceus, nitidus, convexus, latus, dense 
fortiter punctatus, antennis pedibusque rufis; trochanteribus posterioribus valde 
distantibus. Long. 43, lat. 23 m.m. 
Antenne 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. Coxze 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. 
913. 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. 44 m.m., lat. 3 m.m. 
