502 On Aquatic Carnivorous Coleoptcra or DytiscidcB. 



broader and more oval in outline, and the hind legs are decidedly more developed 

 for swimminsr, being: shorter and stouter. 



Abyssinia, (found by Raflfray). 782. 



684. Agabus marginalis, n. sp. — Ovalis, sat convexus, laevis, iiitidus, niger, 

 capite anterius prothoraceque lateribus rufescentibus, elytris fusco-rufis, basi lateri- 

 busque dilutioribus, antcnnis tibiisque anterioribus rufis, femoribus pedibusque 

 posterioril)us jnceis. Long. Zi, lat. 4i ni.m. 



fn this species the prosternal process is rather peculiar ; the space separating the 

 fi-ont 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 coxse, it is a little elevated 

 along the middle, and i« 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 Dyti-cus 

 brunneus (No. 688), and may be considered intermediate between 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). 78.3. 



Group 3. 



Outline of thorax and elytra continuous ; 2^''ostcrnal iJrocess very broad and fiat, 

 polished : middle coxce rather widely separated, with highly developed metasternal 

 impression ; hind coxse 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, M.C. — Ovalis, baud convexus, 

 pernitidus, niger, antennis pedibu.sque rufis, femoribus plus minusve picescentibus, 

 elytris pone medium versus latera lineola, et ante apicem gutta, testaceis ; supra 

 undique conspicue sed baud profunde reticulatus, reticulis magnis ; prothoracis 

 margine laterali nuUo modo crasso. Long. 8, lat. 4l 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 sim^jle, and are scarcely more developed than in the 

 female. 



