On Aquatic Carnivorous Coleoptera or Dytiscide. 479 
624. Hydroporus rufilabris, n. sp.—Oblongo-ovalis, fere depressus, evidenter 
pubescens, subtilissime punctatus, subnitidus, nigricans, capite anterius, pedibus 
prothoracisque lateribus rufis, antennis fuscis, basi rufo; subtus nitidus, coxis 
posterioribus obsolete punctatis, abdomine tantum basi utrinque punctato ; prosterni 
processu Jeviter compresso, medio sat carinato. Long. 4, lat. 24 m.m. 
Mas, tarsis anterioribus leviter dilatatis. 
This species is ailied to H. modestus, (No. 627), but is readily distinguished by 
the smaller size, and by the much slighter differences between the sexes. 
North America, (Texas ; a pair of this species I received from Belfrage as H. rufilabris, Zimm.) 330. 
625. Hydroporus ruficeps, Aubé, M.C.—pOblongo-ovalis, sat convexus, evidenter 
pubescens, obsolete punctatus, opacus, nigricans, antennis pedibus capiteque rufis, 
thoracis elytrorumque limbo rufescente; subtus sat nitidus, coxis posterioribus 
crebre evidenter punctatis, abdomine polito, tantum basi utrinque punctato, limbo 
rufescente ; prosterni processu vix compresso, sed medio longitudinaliter distincte 
elevato. Long. 42, lat. 23 m.m. 
T have seen of this species only females ; they may be readily distinguished from 
that sex of H. modestus (No. 627), by the more punctured hind coxee; they have 
the prosternal process a little less compressed, and show several other small differ- 
ences. 
North America, (Massachusetts). 329. 
626. Hydroporus axillaris, Lec., M.C.—sHlongato-ovalis, convexus, densius sub- 
tiliter pubescens et punctatus, subopacus, nigricans, antennis pedibusque rufo- 
obscuris, elytris fuscis limbo diiutiore ; prosterni processu fortiter compresso, coxis 
posterioribus omnino obsolete panctatis, abdomine distinctius, segmento apicali 
dense punctato. Long. 5, lat. 25 m.m. 
A single typical specimen from the cabinet of Dr. Leconte, is all I have seen ot 
this species; though it is deprived of its tarsi, I have no doubt it isa male. It 
is different in form from H. modestus, being narrower in front, and may very 
readily be distinguished by the more punctate ventral segments. 
North America. 328. 
627. Hydroporus modestus, Aubé, M.C.—Oblongo-ovalis, fere depressus, evidenter 
pubescens, obsoletis-ime punctatus, nigricans, prothoracis lateribus elytrorumque 
limbo laterali dilutioribus, pedibus rufis, antennis basi rufo, apice fusco; subtus 
nitidus coxis posterioribus omnino obsolete punctatis, abdomine polito, tantum 
basi utrinque punctato, lateribus seepius rufo-maculatis ; prosterni processu leviter 
compresso, medio evidenter carinato-elevato. Long. 5, lat. 25 m.m. 
