On Aquatic Carnivorous Coleoptera or Dytiscidce. 463 



573. Hydroporus raaurus, n. sp. — Ovalis, convexus, subtiliter sed evidenter 

 pubescens, dense subtiliter punctatus, nitidus, niger, antennis pedibusque fuscis, 

 illis basi rufescente ; coxis posterioiibus crebre sat fortitei* punotatis ; abdomine 

 segmento ultimo satis pubescente, dimidio apicali indistincte punctate. Long. .31, 

 lat. 2 m.m. 



This species is distinguished from Dytiscus planus, (No. 575), by its smaller size, 

 black colour, and rather liner punctuation : it is equally similar to Hyphydrus 

 pubescens, (No. 568), but is darker in colour, more finely punctured, has the tliird 

 joint of the front tarsi larger, and the apical ventral segment indistinctly punctured. 

 The sexes seem scarcely distinguishable. 



Southern Europe : (Spain, Guadarrama, Grenada). 379. 



574. Hydropoi'us inscitus, n, sp. — Ovalis, gracilis, minus convexus, subtiliter 

 pubescens, crebre subtiliter punctatus, subnitidus, niger, antennis, pedibus, thoracis 

 margine lateral! elytrisque testaceis, his hie inde irregulariter infuscatis ; coxis 

 posterioribus sat crebre parum fortiter punctatis; abdomine segmento ultimo 

 subtiliter punctate. Long. 4a, lat. 1\ m.m. 



This species is allied to Dytiscus planus, (No. 575), but is more slender, more 

 finely punctured and pubescent, and less dark in colour. It more resembles 

 Hydroporus nigrice[is, (No, 576) hi colour, but the fine punctuation and pubescence 

 readily distinguish it therefrom. 



I have seen only a single female. 



Mesoiiotamia (Dr. C. Milliiigen). 1148. 



575. Dytiscus planus. Fab., Hydroporus planus, M.C. — Ovalis, minus convexus, 

 evidenter pubescens, dense subtiliter punctatus, subnitidus, niger, elytris fuscis, 

 circa humeros ssepe dilutioribus, pedibus rufescentibus, antennis fuscis basi rufo ; 

 coxis posterioiibus crebre sat fortiter punctatis ; abdomine segmento apicali satis 

 pubescente, dimidio apicali dense punctato. Long, ih, lat. 2l m.m. 



The sexes are not easy to distinguish, but the male has the front tarsi distinctly 

 broader than they are in the female. The species varies much in size, and a good 

 deal in colour; it may always be distinguished from Hyphydrus pubescens, (No. 

 568), by the larger third joint of the front tarsi, and the different sculpture of the 

 apical ventral segment. 



Europe, one of the commoner species ; from G0° 50' ui Finland, (Sahlberg) to the Guadarrama and 

 Corsica. 378, 



576. Hydroporus nigriceps, Schaum, M.C. — Ovalis, minus convexus, dense 

 evidenterque pubescens, dense subtiliterque punctatus, niger, antennis pedibuscjue 



