646 On Aquatic Carnivorous Coleoptera or Dytiscida. 
really belongs to this species ; it is very narrow, and has the coxal processes shorter 
and the epipleurz narrower than any other specimen I have seen. 
Northern Europe and Siberia: extending southwards in the mountains to the Basses Alpes, and 
Northern Italy, but otherwise not found more to the South than Northern Germany and Central Russia. 
(Lapland, Scotland, Ireland, Stettin, Berlin, Kasan ; Barcelonette ; Lago della Maddalena.) 951. 
Group 3. 
1003. Dytiscus latissimus, Linn., M.C.—Subtus ferrugineus, supra niger, protho- 
race limbo omni elytrisque flavo-marginatis, antennis pedibusque rufis, tarsis 
posterioribus plus minusve picescentibus ; epipleuris dilatatis ; prosterni processu lato 
et brevi ; coxarum processubus apicibus distantibus, acuminatis, parum prolongatis : 
labro medio vix emarginato. Long. 40, lat. 25 m.m. 
Mas, sat nitidus, elytris apicem versus tantum subtilius punctulatis. 
Fem., subopaca, prothorace medio utrinque subtilissime punctulato, elytris longe 
ultra medium suleatis, interstitiis dense subtilissime punctatis, apice crebre sub- 
tiliter punctatis, punctisque majoribus parum numerosis. 
In the male of this species the small palettes of the front tarsi remain unde- 
veloped, being no larger than those of the intermediate feet. The species is re- 
markable by the dilated epipleuree with a sharp external edge, and by the fine 
punctuation of the sulcate female ; the yellow band at the apex is divided into two 
narrow widely separated portions, the anterior of which is unusually distinct. 
The species varies but little, but sometimes there is a more or less extensive 
appearance of yellow colour on the middle of the wing-cases in the female : notwith- 
standing the large size of the species, the hind femora are remarkably slender. 
The species is extremely liable to abnormal developments of different parts of the 
skeleton. An individual possibly a hybrid between this and D. marginalis, or D. 
dimidiatus has been described by Kraatz, Berl. Ent. Zeit. XVIII, p. 293, pl. I, 
f, 2, but as the description and figure quite agree with D. harrisii, I am inclined to 
believe that the supposed hybrid may prove to be an individual of that species. 
Northern Europe ; (and N. America ?). (Sweden ; Finland to 63°,sec. Sahlberg; Germany; Vosges). 952. 
Grotvp 4. 
1004. Dytiscus harrisi, Kirb, M.C.—Latus, robustus ; subtus testaceo nigroque 
variegatus, supra niger, prothorace limbo omni elytrisque flavo-marginatis, antennis 
picee rufis, femoribus testaceis, tibiis et tarsis pedorum quatuor posteriorum nigri- 
cantibus ; prosterni procesu brevi et lato ; coxarum processubus brevibus, rotundatis ; 
labro haud emarginato. Long. 40, lat. 22 m.m. 
