40G On Aquatic Cnrnivorons Cohoptcra or Di/titscidui. 



Mas, supra nitidus, tarsis anterioribus et intermediis dilatatis, anterioribus 

 unofuiculo interno crassiore et masfis curvato. 



Fern, (a) fere ut in mare punctata et nitida. 

 (h) omnino opaca, obsolete punctata. 



The two forms of the female seem to have a different geographical distribution. 

 In the northern part of its area it is cliiefl}^ if not solely, the dull form that is 

 found, while in the south this form seems to be absent. In Central Europe both 

 forms are found. 



Europe ; Corsica, North Africa. In brackish aud fresh waters, widely distributed, Init absent from 

 tlie north of Europe. 200. 



417. Hydroporus novemlineatus, Steph., M.C. — Ovalis, sat elongatus, sine pubes- 

 centia, testaceus, thoracis macula media, elytroruna lineis quatuor elongatis, pectore 

 abdomineque nigris ; elytris dense subtiliter sed distincte punctatis ; prothorace 

 medio foveola minuta ; cosis posterioribus crebi-e sat subtiliter punctatis. Long. 

 4, lat. 2 m.m. 



il/a.% supra sat nitidus, tarsis anterioribus et intermediis fortiter dilatatis, 

 anterioribus unguiculo interno breviore et crassiore, magis curvato, apice acuminato. 



Fern., (a) supra omnino opaca. 



(h) ut in mare punctata et nitida. 



In Scotland I have found only the dull form of the female; but of two specimens 

 of that sex sent me from Karelia by Dr. Sahlberg, one is the dull form, the other 

 the shining one. 



Nortliern Eiu'ope. (Found in hikes in Scothxnd and Lapland). 109. 



418. Hydroporus lautus, Schaum, M.C. — "Ovalis, oonvexiusculus, supra testaceus, 

 capite postice prothoracisque puncto medio nigris, elytris j^arce subtiliter punctulatis, 

 lineis quatuor nee basin nee apicem attingentibus nigris : pectore utrinque sparsim 

 sat fortiter punctate. Long. If, lin." 3'- m.m. 



3Ias, nitidus, tarsis anterioribus et intermediis fortiter dilatatis. 



Fern., " opaca subtilius punctata." (ex Schaum.) 



The claws on the front foot of the male are very fine, but the anterior one is 

 stouter than, aud twice as long as the minute hinder one. The comparatively 

 short broad form of the species gives it some resemblance to Dytiscus confluens, 

 (No. 423). 



Europe : Germany. (This species was found in brackish water near Halle, about thii-ty years ago ; a 

 single pair is all I have seen of it). 198. 



419. Hydroporus enneagrammus, Ahrens, Hydroporus nigro-linentus M.C. — 

 Oblongo-ovalis sat convexus, sine pubescentia, testaceixs, pectore abdomineque 



