424 On Aquatic Carnivorous Coleoptera or Dytiscide, 
female, and the front ones have the claws longer and stouter; the thorax is not 
narrowed in front of the base so that its hind angles are free, the base being a 
little wider than the shoulders of the elytra; in the female the sides are a good 
deal contracted just in front of the base so that the angles fall within the shoulders 
of the elytra; in the female there is a short indistinct plica near the outer edge 
of the elytra at some distance before the apex, and the last ventral segment is a 
little prominent on each side. 3 
Central Europe; (widely distributed but rare ; from Scotland to Italy, and from Dalinatia to La 
Vendée). 300. 
ZROUP 2. 
462. Dytiscus duodecim-pustulatus, Fab., Hydroporus duodecim-pustulatus, 
M.C.—Oblongo-ovalis, sine pubescentia, sub-opacus, testaceo-ferrugineus, thorace 
anterius et posterius nigricante, elytris fusco-nigris, maculis fere quadratis testaceis 
ornatis ; thorace lateribus valde rotundatis, angulis posterioribus obtusis ; corpore 
subtilissime punctulato. Long. 53, lat. 27 m.m. 
Mas, tarsis anterioribus et intermediis bene dilatatis, anterioribus unguiculis 
majoribus, tibiis anterioribus et intermediis intus leviter curvatis, intermediis 
angulo apicali interno unco parvo armatis. 
This species varies a good deal in colour, the elytra bemg sometimes nearly 
entirely yellow while in other individuals the black colour occupies nearly all their 
surface ; the underside also is more or less infuscate. 
Central and Southern Europe, (and Algeria ?) ; extends in the north to Scotland, and south of Sweden, 
wanting in Finland. 240. 
463. Hydroporus duodecim-maculatus, Regt. Ann. Soc. Fr. 1877, p. exxxii.— 
Oblongo-ovalis, sine pubescentia, testaceo-ferrugineus, capite intra ocules, vertice, 
thoraceque anterius et posterius nigro-marginatis, elytris nigris, maculis plus minusve 
conspicuis testaceis ornatis; thorace lateribus valde rotundatis, angulis poster- 
ioribus fere rotundatis; corpore subtus plus minusve infuscato. Long. 52, lat. 
vix 3 m.m. 
Mus, paulo longiore, tarsis anterioribus et intermedius bene dilatatis; tibius 
intermediis intus curvatis, angulo apicali interno unco parvo armatis. 
Fem., opaca omnium dense subtilissime punctata. 
Although very closely allied to Dytiscus duodecim-pustulatus the specimens 
before me of this species differ not only by their more rounded hind angles of the 
thorax, but also by the sexual characters, the male front claws being shorter, and 
the anterior tibize not curved inwardly, while the female differs more in appearance 
from the male owing to the punctuation of the surface being more obsolete. The 
colour no doubt varies a goud deal. 
