502 On Aquatic Carnivorous Coleoptera or Dytiscida. 
broader and more oval in outline, and the hind legs are decidedly more developed 
for swimming, being shorter and stouter. 
Abyssinia, (found by Raffray). 782. 
684. Agabus marginalis, n. sp.—Ovalis, sat convexus, levis, nitidus, niger, 
capite anterius prothoraceque lateribus rufescentibus, elytris fusco-rufis, basi lateri- 
busque dilutioribus, antennis tibiisque anterioribus rufis, femoribus pedibusque 
posterioribus piceis. Long. 73, lat. 44 m.m. 
In this species the prosternal process is rather peculiar ; the space separating the 
front legs is broad, but the prosternal process is not very much dilated behind, so 
that it is not greatly wider than the space between the coxe, it is a little elevated 
along the middle, and is finely punctured at the sides. The species greatly resembles 
Dytiscus paludosus (No. 680), but is larger, has the lateral margin of the thorax finer, 
and the hind legs shorter and stouter ; in some respects it approximates to Dytiscus 
brunneus (No. 688), and may be considered intermediate hetween it and D. palu- 
dosus, but it is not so broad and is differently coloured and has the prosternal 
process very different. I have seen only the female. 
Europe. (Greece, Styria). 783. 
Group 3. 
Outline of thorax and elytra continuous ; prosternal process very broad and flat, 
polished ; middle coxe rather widely separated, with highly developed metasternal 
impression ; hind coxee rather well developed, the wings of the metasternum rather 
short ; swimming legs moderately slender. 
Three species from the New World. 
685. Colymbetes obtusatus, Say, Agabus obtusatus, .C.—Ovalis, haud convexus, 
pernitidus, niger, antennis pedibusque rufis, femoribus plus minusve picescentibus, 
elytris pone medium versus latera lineola, et ante apicem gutta, testaceis; supra 
undique conspicue sed haud profunde reticulatus, reticulis magnis; prothoracis 
margine laterali nullo modo crasso. Long. 8, lat. 43 m.m. 
The male has the basal joints of the front and middle tarsi a little incrassate, and 
furnished beneath with short hairs which bear quite distinct palettes: the claws of 
the front feet are very nearly simple, and are scarcely more developed than in the 
female. 
