536 On Aquatic Carnivorous Coleoptera or Dytiscidce. 



754. Agubus clavatus, Lee, M.C. — Obloiigo-ovalis, sat convexus, fere angustus, 

 nitidus, sublaevigatus, ferrugineus, antennarum palparumque apicibus fuscis ; 

 prothorace fere brevi, margine lateral! sat crasso. Long. 8, lat. 4 m.m. 



The male has the five apical joints of the antennae dilated and flattened, and 

 when the underface of the joints is looked at each is seen to be somewhat distorted 

 or sinuate near the farther inner angle; the basal joints of the front and middle 

 tarsi are a little incrassate, and are somewhat amply furnished beneath with rather 

 small oval palettes ; the claws are slender and simple, the front one being longer 

 than the hind one, and but little curved. The female I have not seen. The upper- 

 surface when carefully examined is seen in this species to be sparingly and exces- 

 sively minutely punctulate. 



North America, (Kansas). 809. 



7 00. Dytiscus serricornis, Payk., Agahus serricornis, M.C. — Ovalis, convexus, 

 subopacus, ferrugineus, supra fusco-feneus, limbo plus minusve ferrugineo ; pro- 

 thorace elongate, antrorsum fortiter angustato, angulis posterioribus subrotundatis, 

 margine laterali hand lato ; elytris opacis subleevigatis. Long, c? 11, lat. 6 m.m. 



The male is considerably larger than the female, and has the four apical joints of 

 the antennpe dilated and flattened, and excavate beneath ; the front femora are 

 furnished beneath with long dense cilite ; the hind legs are very peculiar, their 

 femora are a little depressed or thinned near the trochanters, the tibiae have their 

 lower face somewhat curved, and their inner edge densely ciliate, and the basal 

 joint of the tarsus has its lower face much curved, and densely ciliate ; the front and 

 middle tar.si have their basal joints much incrassate and compressed and amply 

 furnished beneath with moderately large, rounded palettes ; the claws of the front 

 feet are elongate, slender, and nearly straight. There is no sexual difference of 

 sculpture, and when the upper surface is examined, its dullness is seen to arise 

 from its being excessively finely and densely reticulate, and it is also seen to be 

 excessively minutely and sparing^ punctulate. 



North Europe, and Siberia; (Sweden; Finland to 69° 40' North, Sahlberg). 810. 



756. Agabus clavieornis, n. sp. — Ovalis, sat convexus, subopacus, piceus, supra 

 senescens, antennis rufis ; prothorace sat elongato, antrorsum sat angustato, angulis 

 posterioribus subrotundatis, margine laterali hand lato ; elytris opacis sublsevigatis. 

 Long. IO5, lat. 6 m.m. 



The male is broader than the female and has the four apical joints of the antennje 

 dilated and flattened, and excavate beneath ; the front femora are densely ciliate 

 beneath ; the front and middle tarsi are very broad and but little compressed, and 

 are furnished beneath with large palettes ; the claws of the front feet are elongate, 



