On Aquatic Carnivorous Colecptera or Dytisciche. 513 



one species. Gaurodytes coriaceus, Sahl., (Not. Fenn. XIV, p. 174) is also I think 

 a variety of the female of this species. 



This appears to be an arctic, aljiine, and subalpine species. 



Europe, Siberia, Greenland, North America, (Sweden, Finland, Lapland, Britain, Germany, France, 

 Northern Italy ; Labrador, Hudson's Bay, White Mountains). 744. 



707. Agabus borealis, {dissimills, Said.), n. sp. — Oblongo-ovalis, hand convexus, 

 Stubnitidus, niger, supra fusco-seneus, elytris versus latera j^allidioribus, antennis 

 pedibusque rufis, illis fusco-maculatis, prothorace margine laterali tenuiore ; elytris 

 sat nitidis (cj), vel fere opacis {$). Long 6i, lat. 3i m.m. 



This is probably another variety of Dytiscus congener, with which I have not 

 however united it, as the males have the surface of the elytra rendered a little 

 silky by an exce.ssively fine and indistinct sculpture. The male tarsi, and the 

 other structural characters show no diflerence from D. congener. 



Arctic Siberia, (found by Dr. Sahlberg). 745. 



708. Colymbetes ambiguus, Say, Agabus ambiguus, M.C. — Ovalis, vix convexus, 

 niger, elytris rufescentibus, antennis pedibusque rufis, his femoribus nigricantibus, 

 prothorace margine laterali baud lato ; prosterni processu elongato, angusto, 

 acuminato, lateribus sat compressis, punctulatis. Long. 6|, lat. 3| m.m. 



I have seen but two specimens in bad condition, and find the only important 

 difference from Dytiscus congener, to be the more carinate and less smooth 

 prosternal process ; I have not seen the female : the male has the tarsi formed as 

 in Dytiscus congener (No. 706) ; I shall not be surprised if the examination of 

 other individuals, show this supposed species to be not distinct from Dytiscus 

 congener. 



The identification with Say's description is by no means a certainty. A specimen 

 was sent me by Leconte as being his A. morosus. 



North America, (California). 746. 



709. Agabus mntus, n. sp. — Ovalis, parum convexus, nitidus, baud reticulatus, 

 nigricans, elytrorum lateribus dilutioribus, prothorace subaenescente, antennis pedi- 

 busque rufis. Long. 6i, lat. 3i m.m. 



The male has the basal joints of the front and middle tarsi scarcely incrassate, 

 and. having therefore a very small area beneath furnished with sexual clothino- ; 

 the front claws are a little longer than in the female, nearly straight, and a little in- 

 crassate or laminate ; the female is rather duller than the male but has no reticulation. 



The species is closely allied to Dytiscus congener (No. 706), but is rather smaller 



