On Aquatic Carnivorous Coleoptera or Dytiscide. 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 margine laterali parum elevato; tarsis posterioribus articulo quarto 
longius lobato-producto. Long. 104, lat. 54 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 sculpture 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. Rhantus sericans, n. sp.—Ovalis, sat convexus, nitidus, subtus niger, 
prosterno laminaque communi coxarum posticarum testaceis, abdomine maris nigro, 
segmentis vix rufo-fasciatis, (feminee inviso); 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 ; tarsis posterioribus articulo quarto vix 
lobato-producto. Long. 10, lat. 5s 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 bistriatus, M.C—Ovalis, parum con- 
vexus, subtus niger, prosterno testaceo, coxarum posticarum processubus plus 
minusve rufescentibus, abdominis seementis parum distincte rufo-marginatis ; supra 
testaceus, vertice nigro-variegato, prothorace basi in medio argute nigro, elytris 
creberrime nigro-irroratis, antennis pedibusque rutfis, illis extrorsum fuscescentibus, 
elytris creberrime equaliter reticulatis. Long. 10, lat. 54 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 
TRANS. ROY. DUB. SOC., N.S., VOL, II, 41 
