On Aquatic Carnivorous Coleoptera or DijtiscidcB. 331 



Antennae rather short, and stout. Clypeus extremely obsoletely margined. 

 Thoracic punctuation very slight. Elytra rather sparingly but distinctly and evenly 

 punctured. Ccjxce sparingly punctured. 



This species is intermediate in form between Hydrovatus and a small Hydroporus, 

 but in its structure it departs but little from Hydrovatus clypealis (No. 179). 



Australia, (Rockhampton). 18. 



208. Hydrovatus pumilus, n. sp. — Oblongus, minus couvexus et elongatus, sat 

 nitidus, testaceus, sparsim subtiliter punctatus, ad apicem breviter acutus ; coxis 

 posterioribus sparsim obsolete punctatis. Long. IJ, lat. 1 m.m. 



Though very closely allied to H. parallelus, this is a little smaller and decidedly 

 shorter. It is the smallest species of the genus and the one in which the articula- 

 tions of the hind legs are least separate. 



Sumatra, (two individuals sent by Wehncke). A specimen from " India " sent also from Welincke differs 

 in being a little less shiuiog. 451. 



209. Hydrovatus opacus, n. sp. — Latus, brevis, ferrugineus, evidenter reticulatus, 

 subopacus, crebre fortiter puncfcatus ; antennis sat elongatis ; processu prosternali 

 antice obtuso et apice leviter deflexo. Long. 2f, lat. Ij m.m. 



Mas, antennis crassiusculis, medio leviter incrassatis. 



Fern., antennis sat tenuibus simplicibus. 



Longer but not at all broader than H. cuspidatus, (No. ISO), and with closer and 

 more regular, and rather coarser punctuation, and with the front tibiaj rather lono-er 

 and more slender ; in the female the antennae are rather longer than they are in 

 H. cuspidatus ; and in the male they are a good deal longer than in the female, 

 and the middle joints (especially 4-6), are rather thicker than the others, the tarsi 

 in this sex are also a good deal more dilated than in the other : the form of the 

 point of the prosternal process distinguishes the species from H. confertus (No. 202), 

 and its allies, which it greatly resembles. 



Australia, (Rockhampton). 12. 



210. Hydrovatus obtusus, Motsch., M.C. — Testaceo-ferrugineus, minus latus, 

 ad apicem minus acuminatus, crebre evidenter reticulatus, subtiliter sat crebre 

 punctatus. Long. 2i m.m., lat. Ij m.m. 



Smaller and a good deal narrower than H. cuspidatus, (No. ISO), and much less 

 acuminate behind, and with the punctuation i-ather finer and more evenly distributed. 

 The large punctures on the coxaj are rather sparing and subobsolete, being but 

 little impressed. 



The only specimen I have seen of this species is in the collection of the Brussels 



TOANf. ROT. DUB. SOC, N.S., VOL. H. J X 



