On Aquatic Carnivorous Coleoptera or Dytiscide. 463 
573. Hydroporus maurus, n. sp.—Ovalis, convexus, subtiliter sed evidenter 
pubescens, dense subtiliter punctatus, nitidus, niger, antennis pedibusque fuscis, 
illis basi rufescente; coxis posterioribus crebre sat fortiter punctatis ; abdomine 
seemento ultimo satis pubescente, dimidio apicali indistincte punctato. Long. 25, 
lat. 2 m.m. 
This species is distinguished from Dytiscus planus, (No. 575), by its smaller size, 
black colour, and rather finer punctuation: it is equally similar to Hyphydrus 
pubescens, (No. 568), but is darker in colour, more finely punctured, has the third 
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. Hydroporus inscitus, n. sp.—Ovalis, gracilis, minus convexus, subtiliter 
pubescens, crebre subtiliter punctatus, subnitidus, niger, antennis, pedibus, thoracis 
margine laterali elytrisque testaceis, his hic inde irregulariter infuscatis; coxis 
posterioribus sat crebre parum fortiter punctatis; abdomine segmento ultimo 
subtiliter punctato. Long. 43, lat. 24 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 nigriceps, (No. 576) in colour, but the fine punctuation and pubescence 
readily distinguish it therefrom. 
I have seen only a single female. 
Mesopotamia (Dr. C. Millingen). 1148. 
575. Dytiscus planus, Fab., Mydroporus planus, M. C.—Ovalis, minus convexus, 
evidenter pubescens, dense subtiliter punctatus, subnitidus, niger, elytris fuscis, 
circa humeros spe dilutioribus, pedibus rufescentibus, antennis fuscis basi rufo ; 
coxis posterioribus crebre sat fortiter punctatis ; abdomine segmento apicali satis 
pubescente, dimidio apicali dense punctato. Long. 4, lat. 25 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 60° 50’ in 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 pedibusque 
