On Aquatic Carnivorous Colcoptcra or Dytiscidce. 451 



Mas, antennis articulis intermediis dilatatis. 



This species is very similar to Hydroporus formosus, but has the thorax red 

 across the middle. It varies in the extent of the black marks on the elytra. The 

 Algerian H. Leprieuri (Eeiche, Ann. Fr. 1864, p. 235) is, I consider, a variety of 

 this gpecies. 



Southern Europe, (fsicily, Corsica), Algeria. 322. 



E. 



537. Dytiscus lineatus, Fab., Hydroporus lineatus, M.C. — Ovalis, convexus, 

 posterius acuminatus, parce subtiliter punctatiis, evidenter pubescens, testaceus, 

 prothorace anterius etposterius elytrisque infuscatis,his lineis indistinctis margineque 

 exteriore testaceis ; corpore subtus nitido, coxis posterioribus fortiter punctatis. 

 Long. 3, lat. If m.m. 



Mas, tibiis anterioribus intus versus basin angustatis, tarsis anterioribus et 

 intermediis evidenter dilatatis. 



This species varies in the distinctness of the lines on the elytra, which are some- 

 times nearly obliterated. In Corsica there occurs a small dark form, in which the 

 male characters are less developed than usual : in the examples from the Continent 

 of Europe, the basal joint of the middle tarsus is conspicuously dilated, but in the 

 small Corsican form it is only very slightly so. I have however seen some 

 specimens (also I believe from Corsica) which appear intermediate in these respects. 

 The male of this species is not quite so dull on the upper surface as the female. 



Europe ; Corsica ; common in Continental Europe ; extends in Finland to 68° North, according to 

 Sahlberg. 323. 



538. Hydroporus vicinus, Aube, M.C. — Ovalis, convexus, posterius acuminatus, 

 parce subtiliter punctatus, evidenter pubescens, sujDra fusco-testaceus limbo 

 dilutiore ; subtus testaceus, nitidus, coxis posterioribus fortiter punctatis. Long. 

 'i\, lat. If m.m. 



Mas, sat nitidus, evidenter j^unctulatus, tarsis anterioribus et intermediis latis. 



Fern., opaca, obsolete punctata, tarsis anterioribus et intermediis sat latis. 



This species though very closely allied to Dytiscus lineatus, is more obscure in 

 the colour of its upper surface, and appears to me really distinct ; the distinctions 

 of the sexes being undoubtedly different. 



Tangiers. 324. 



539. Hydroporus genei, Aub^ M.C. — Ovalis, convexus, posterius acuminatus, 

 subtiliter punctatus, evidenter pubescens, subnitidus, ferrugineus, pro thoracis basi 

 elytrisque infuscatis, his macula basali limboque laterali irregulari pallidis ; corpore 

 subtus nitido, coxis posterioribus fortiter punctatis. Long. 3i, lat. If m.m. 



TBAKS. BOX. DUB. SOC, N.S., VOL. II. 3 N 



