406 On Aquatic Curnivorous Coleoptera or Dytiscide. 
Mas, supra nitidus, tarsis anterioribus et intermediis dilatatis, anterioribus 
unguiculo interno crassiore et magis curvato. 
Fem. (a) fere ut in mare punctata et nitida. 
(b) 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 chiefly, 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 and fresh waters, widely distributed, but absent from 
the north of Europe. 200. 
417. Hydroporus novemlineatus, Steph., M.C.—Ovalis, sat elongatus, sine pubes- 
centia, testaceus, thoracis macula media, elytrorum lineis quatuor elongatis, pectore 
abdomineque nigris; elytris dense subtiliter sed distincte punctatis ; prothorace 
medio foveola minuta ; coxis posterioribus erebre sat subtiliter punctatis. Long. 
A, lat. 2 m.m. 
Mas, supra sat nitidus, tarsis anterioribus et intermediis fortiter dilatatis, 
anterioribus unguiculo interno breviore et crassiore, magis curvato, apice acuminato. 
Fem., (a) supra omnino opaca. 
(b) 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. 
Northern Europe. (Found in lakes in Scotland and Lapland). 199. 
418. Hydroporus lautus, Schaum, M.C.—“Ovalis, convexiusculus, supra testaceus, 
capite postice prothoracisque puncto medio nigris, elytris parce subtiliter punctulatis, 
lineis quatuor nec basin nec apicem attingentibus nigris: pectore utrinque sparsim 
sat fortiter punctato. Jong. 1%, lin.” 32 m.m. 
Mas, nitidus, tarsis anterioribus et intermediis fortiter dilatatis. 
Fem., “opaca subtilius punctata.” (ex Schaum.) 
The claws on the front foot of the male are very fine, but the anterior one is 
stouter than, and twice as long as the minute hinder one. The comparatively 
short broad form of the species gives it some resemblance to Dytiscus confluens, 
(No. 428). 
Europe: Germany. (This species was found in brackish water near Halle, about thirty years ago; a 
single pair is all I have seen of it), 198. 
419. Hydroporus enneagrammus, Ahrens, Hydroporus nigro-lineatus M.C.— 
Oblongo-ovalis sat convexus, sine pubescentia, testaceus, pectore abdomineque 
