On Aquatic Carnivorous Coleoptera or Dytiscide. 441 
The male has the front and middle tarsi a little broader than in the female; 
there is extremely little difference in the sculpture of the two sexes. 
This species seems to be a very distinct one, the thorax has the sides without 
any curve, the pubescence of the upper surface is shorter than in the allies, the 
sexual differences are slight, and the coxal lines at the apex are a good deal turned 
outwards. ‘The colour is bright, the yellow markings on the elytra are extensive, 
but are much broken up by longitudinal interruptions of the dark colour. 
Canada, (Coll. Murray). 1143. 
508. Hydroporus clypealis, n. sp.—Ovalis, sat’ latus, tenuiter haud dense 
pubescens, ferrugineus, prothorace anterius et posterius elytrisque nigricantibus, 
his testaceo-signatis ; prothorace tenuiter marginato ; coxis posterioribus fortiter vix 
dense punctatis. Long. 4, lat. 2¢ m.m. 
In the male the front and middle tarsi are moderately dilated, and the claws of 
the anterior ones are a good deal more developed than in the female, and are 
unequal, the front one being a good deal thicker and shorter than the hind one: 
the upper surface is quite shining, the punctuation of the elytra being distinct and 
not dense, while in the female the surface is quite dull and the sculpture obsolete. 
The male of this species is easily distinguished from that of Hydroporus 
undulatus (No. 503), but the females are very similar; the antenne are nearly 
entirely red, however, in the present species, and the punctuation of the hind coxze 
is coarser and not so dense. 
North America, (Massachusetts). 275. 
509. Hydroporus anticus, n. sp.—Ovalis, rufo-testaceus, prothorace basi medio 
maculaque in margine anteriore elytrisque nigricantibus, his signaturis conspicuis 
testaceis ; prothorace tenuiter marginato ; coxis posterioribus fortiter minus dense 
punctatis. Long. 4, lat. 25 m.m. 
I have seen only females of this species, they have the upper surface dull and its 
punctuation obsolete. The coxal lines are in this insect distinctly curved outwards 
at the extremity. 
North America, (Pennsylvania, Louisiana). 276. 
510. Hydroporus consimilis, Lec., M.C.—Ovalis, minus latus, evidenter pubescens, 
dense punctatus fere opacus, lete ferrugineus, prothorace anterius et posterius 
elytrisque nigricantibus, his signaturis conspicuis testaceis ; prothorace tenuiter 
marginato ; elytris dense minus profunde punctatis ; coxis posterioribus fortiter, fere 
dense punctatis. Long. 4%, lat. vix 23 m.m. 
