On Aquatic Carnivorous Coleoptera or Dytiscide. 811 
foveolis frontalibus minus profundis; antennis’ nigris, articulis basi, primis fere totis ferrugineis. 
Prothorax fortiter transversus, niger , limbo crebre sat fortiter punctato, disco parum convexo sublevi ; 
basio medio triangulariter productus, angulis posticis rectis ; lateribus tenuiter marginatis, cum capite et 
elytris fere in eodem arcu rotundatis. Elytra prothorace quintuplo longiora, lateribus equaliter minus 
fortiter rotundata, apice parum acuminata ; disco leviter convexo, tenuissime fusco-pubescentia, nigra sat 
nitida, crebrius evidenter punctata, seriebus punctorum majorum impressis sat discretis, preecipue 
interiore. Corpus subtus nigrum, fere glabrum, sterni lateribus et abdominis basi punctatis. Pedes picei, 
genubus, tarsisque dilutioribus.” 
It is possible this species may prove to be the same as Dytiscus nigrita (No. 561).—D. S. 
1435. Hydroporus submuticus, Thoms., Op. Ent. VI, p. 537. Sweden. 
“Elongatus, glabriculus, niger, pedibus piceo-rufis ; capite majusculo, foveoiis obsoletis ; prothorace 
angulis posticis subrectis, limbo elytrisque crebrius punctatis.” 
“ H.clongatulo affinis sed major, magnitudinefere H. lapponum, foveolisfrontalibus obsoletioribus, elytris 
ventreque basi minus profunde punctatis discedens. Caput majusculum, nigrum, vertice et antice piceum 
obsolete parceque punctatum, foveolis frontalibus parvis haud determinatis. Antenne prothoracis basin 
paullo superantes, nigricantes, basin versus ferruginee ; articulis secundo tertio longiore, hoc quam 
quarto haud transverso sesqui longiore. Prothorax lateribus cum elytris haud continuo rotundatis: basi 
coleopteris vix angustior, medio late productus, angulis posticis leniter obtusis ; margine laterali tenui, 
antrorsum parum angustato, haud rotundato; glaber niger, crebrius punctatus, disco levi. Jilytra 
lateribus pone medium vix dilatata, apice subattenuata: nigra, basi et limbo laterali dilute fusco-piceis, 
hoc linea nigra laterali; supra vix pubescentia, minus crebre, subtiliter punctata, seriebus e punctis 
majoribus haud conspicuis. Corpus subtus nigrum, segmentis 3 primis lateribus sat crebre, minus 
profunde punctatis ; prosterno antice inter basin coxarum processu parvo palpos excipiente, instructo. 
Pedes piceo-rufi.” 
1436. Hydroporus subtilis, Lec., Ann. Lyc. V, p. 206. California. 
“ Oblongus, postice subacutus, piceus, subtiliter punctatus, nitidus, capite parce punctulato, thorace 
antrorsum angustato, rufo, antice posticeque nigricante, lateribus paulo rotundatis, tenuissime margi- 
natis, cum elytris angulum vix formantibus, striola basali profunda ; elytris macula quadrata pone 
humerum, alteraque marginali pone medium rufis, stria suturali distincta. Long. ‘06, specimen unicum 
ad Sta. Isabel.” 
According to a specimen recently communicated to me by its describer, this species is to be placed in 
Bidessus, group IV ; the elytra possess a rather obscure sutural line ; it may go near No. 261.—D.S8. 
1437. Hydroporus subtonsus, Lec., Proc. Ac. Phil., 1855, p. 297. North America. 
«< Longior ovalis, parum conyexus, parce pubescens, niger, ore rufescente, thorace lateribus, vix margi- 
natis rufescentibus cum elytris angulum obtusum formantibus, angulis posticis rectis, disco parce subtilius, 
ad basin et latera distinctius punctato, elytris seepe testaceo-piceis, modice punctatis, pedibus rufo-testaceis. 
Long. 125.” 
“Lake Superior and Vermont. Resembles in appearance H. varians and H. puberulus, and likely to 
be confounded with them. H. varians is narrower and more oblong, the sides being almost parallel at 
the middle, and is entirely glabrous. H. puberulus has the posterior angles of the thorax obtuse and 
very distinctly impressed. The elytra of the female are less shining and less deeply punctured than those 
of the male.” 
This is placed by Crotch next to D. tristis (No. 602).—D. 8. 
TRANS. ROY. DUB. SOC., N.S., VOL, IL. 5 M 
