2G0 



On Aquatic Carnicorous Coleoptera or Dytiscidce. 



3. Pelobius niger, Clark. Ilydrachna nujva, M.C — Convexus, sine pubescentia, 

 sat nitidus niger, antennis pedibusque ferrugineis, prothorace dense fortiter 

 punctato ; elytris crebre punctatis, basi rugosis ; corporc subtus fortiter punctate. 

 Long. 9, lat. 55 m.m. 



I have seen only females of this species. 



Australia, (Queensland). 237. 



III. 1.— Tribe NOTERIDES. 



Scutellum quite invisible ; internal lamina of posterior coxa very differentiated 

 from the exterior lamina, the two separated by a nearly longitudinally straight 

 demarcation which extends the whole length of the coxa : the anterior border of 

 the hind coxa gains its nearest approach to the middle coxa before it has extended 

 in the lateral direction half way towards the epipleura : Front and middle tarsi 

 conspicuously five-jointed. Anterior tibia frequently with a hook or curved spur 

 at the extremity. 



( Note. — In Notomicrus theanterior border of the hind coxa cannot be made out, the suture between it and 

 tlie metasternum being quite obliterated, but the peculiar form of the internal lamina cannot be mistaken.) 



Coxo-metasternal suture obliterated ; hind ] 



coxal cavities little separated; no coxal ,■ NOTOMICRUS (vide helovf). 



W 

 I— I 



w 



H 

 O 



line or border. 



i 



§ g 8 



u 2 '-3 



to ' ^ C3 



C i p 



O K. «3 



o g 2 



Hind coxal cavities much separated ; coxal | hYDROCOPTUS (vide p. 2G1). 

 line and border present, although line. j \ i / 



Prosternal process rounded behind; hind 1 -^ - i .■ ? 9r'?\ 



femora without angular ciliie. j ' ^ i • ~ /• 



Prosternal process truncate behind; hind ] 

 femora with angular cili;i? ; hind coxal > 



cavities separate. 



SuPiiisiNi (viile p. 267). 



Prosternal process truncate behind ; hind 1 



femora with angular cilise ; hind coxal HYDROCANTnisi (vtrfe p. 268). 

 cavities contiguous. j 



I. 2.— Genus NOTOMICRUS. 

 Anterior tibia destitute of a curved spur, and with iuduBnite outer apical angle; 

 posterior coxal cavities but little separated, coxal notch scarcely visible. 

 The extremely minute species are found in Australia and South America. 



4. Notomicrus loBvigatus, n. sp. — Ovalis, ;ingustulus, subdepressus, per-nitidus, 

 Ifevigatus, impunctatus, testaceus, pectore abdominisque basi fuscis ; tarsis posterior- 

 ibus filiformibus, tibiis longioribus. Long. \\, lat. I m.m. 



I see no sexual differences in the few specimens I have seen of this minute beetle. 



Australia, (Rockhampton, Brisbane). 4G8. 



