On Aquatic Carnivorous Coleoptcra or Dytiscidce. 333 



Closely allied to H. nigricans, but broader and with the upper surface nearly 

 opaque ; but readily distinguished by its shorter, broader antennse. 



I have seen only a single male, whose front and middle tarsi are distinctly 

 dilated. 



Madagascar. 150. 



214. Hydrovatus badeni, (AVehncke), n. sp. — Nigro-piceus, latus, convexus, dense 

 fortiter punctatus, antennis pedibusque rufis. Long. 4?, lat. Ss m.m. 



Mas, nitidus, antennis sat elongatis et gracilibus, tarsis anterioribus et inter- 

 mediis dilatatis. 



Fern., opaca, magis obsolete punctata, antennis paulo brevioribus, tarsis latius- 

 culis, sed articulis basalibus haud dilatatis. 



Allied to Hydrovatus nigricans, (No. 212), but a good deal larger and with great 

 differences between the two sexes. 



Madagascar. 151. 



215. Hydrovatus compactus, n. sp. — Convexus, ferrugineus, nitidus, lateribus 

 valde rotundatis, crebre sat fortiter punctatus ; trochanteribus j)osterioribus valde 

 distantibus. Long. 3^, lat. 2i m.m. 



Antennre rather long and slender ; clypeus with a distinct and uninterrupted 

 margin. Thorax closely and distinctly punctured. Elytra rather closely and 

 coarsely punctured. Coxpe externally rather closely punctured. The general 

 form is very convex and compact, and greatly rounded at the sides, so as to be much 

 narrowed in front and behind. 



This species is closely allied to Hydrovatus nigricans, (No. 212), but is paler in 

 colour and much smaller, it is even more convex and the elytra are less elongate. 

 The individual described is a male but the tarsi are only about half as broad as in 

 the (J of H. nigricans. In my collection there is a specimen which, from its resem- 

 blance in form, I believe to be the female of this species, but it differs remarkably 

 from the S by its sculpture, the whole of the upper surface being quite dull, densely 

 reticulate, and with the sculpture obsolete, and the punctuation of the coxae is finer 

 and more sparing. 



Africa, (Gaboon). 20. 



216. Hydrovatus nigrita (Wehncke), n. sp. — Nigro-piceus, nitidus, convexus, latus, 

 dense fortiter punctatus, antennis pedibusque rufis ; trochanteribus posterioribus 

 bene distantibus. Long, fere 4, lat. 22 m.m. 



Extremely like Hydrovatus nigricans, (No. 212), but rather smaller and distinctly 

 narrower, the antennse slightly shorter, the hind and middle legs not quite so widely 



3X2 



