On Aquatic Carnivorous Coleoptera or DytiscidcB. 619 



maculato, supra testaceus, vertice nigro-variegato, thorace disco plaga transversa 

 nigra, elytris creberrime nigro-irroratis, antennis pedibusque flavis, illis extrorsum 

 fuscescentibus ; elytris creberrime reticulatis, parte basali magis strigosulo ; 

 prothorace niargine laterali parum elevato ; tarsis posterioribus articulo quarto 

 longius lobato-producto. Long. lOi, lat. 5i m.m. 



The male has the basal joints of the front tarsi much incrassate, and comparatively 

 little compressed, and presenting therefore a broad sole, clothed with moderately 

 large palettes, and with long marginal hairs having beautifully curled extremities ; 

 the front claws are long and very unequal, the anterior being much longer than 

 the other ; the middle tarsi are clothed beneath in a similar manner to the front 

 ones, and have their terminal joints elongate, and bearing rather long unequal 

 claws. 



The females are often quite similar in sculj^ture to the males, but sometimes 

 bear on the basal part of the elytra very short deep impressions, varying greatly in 

 number and extent. 



Europe, (Sweden, Finland, England, France, Belgium, Germany, Northern and Southern Russia). 

 894. 



948. ilhantus sericans, n. sp. — Ovalis, sat convexus, nitidus, subtus niger, 

 prosterno laminaque communi coxarum posticarum testaceis, abdomine maris nigro, 

 segmentis vix rufo-fasciatis, (feminae inviso) ; supra testaceus, vertice nigro- 

 variegato, thorace disco pJaga transversa nigra, elytris creberrime nigro-irroratis, 

 antennis pedibusque flavis, illis extrorsum fuscescentibus ; elytris creberrime 

 reticulatis, parte basali magis strigosulo ; tarsis posterioribus articulo quarto vix 

 lobato-producto. Long. 10, lat. 5i m.m. 



This species seems excessively close to Dytiscus notatus, and differs chiefly by 

 the more truncate external hind margin of the fourth joint of the hind tarsi ; 

 according to the two males before me it is rather smaller in size and has the ventral 

 segments less variegated with red. 



North America, (British Columbia). 895. 



949. Dytiscus bistriatus. Berg., Rhantus histriatus, M.C. — Ovalis, parum con- 

 vexus, subtus niger, prosterno testaceo, coxarum posticarum processubus plus 

 minusve rufescentibus, abdominis segmentis parum distincte rufo-marginatis ; supra 

 testaceus, vertice nigro-variegato, prothorace basi in medio argute nigro, elytris 

 creberrime nigro-irroratis, antennis pedibusque rufis, illis extrorsum fuscescentibus, 

 elytris creberrime sequaliter reticulatis. Long. 10, lat. Si m.m. 



The male has the front tarsi a good deal incrassate and moderately compressed 

 and bearing beneath four rows of moderately large palettes, and well developed 

 marginal hairs with curved extremities, their claws are long and about equal ; the 



TBANS. EOT. DUB. SOC, U.S., VOL. II. * I< 



