4S { On Aquatic Carnivorous Coleoptera or Dytiscide. 
The male has the front and middle tarsi rather strongly dilated, and the 
front tibize excised at the base inwardly: the only female individual I have seen is 
dull and opaque, but distinctly punctured, its front tibiee are not excised. Though 
very closely allied to Hydroporus collaris, the species is quite distinct. 
North America, (United States). 403. 
Grotp 8. 
640. Hydroporus terminalis, n. sp.—Ovalis, angustulus, minus convexus, sine 
pubescentia, subnitidus, abdomine pectoreque nigris, supra fusco-testaceus, pedibus 
sordide rufis, antennis fuscis basi testaceo ; prothorace valde transverso, inconspicue 
punctato ; elytris crebre subtiliter punctatis, punctis versus apicem magis conspicuis; 
coxis posterioribus sat evidenter punctatis. Long. 3, lat. 13 m.m. 
The front tarsi in the male are rather broader than in the female. This species 
is extremely similar to Ilydroporus vilis, Lec., but is a little narrower, the antenne 
are darker in colour, the punctuation is rather more conspicuous, and all the tarsi 
are smaller. 
North America, (California). 404. 
641. Hydroporus vilis, Lec., M.C.—Ovalis, minus convexus, sine pubescentia, 
subnitidus, abdomine pectoreque nigris, sipra fusco-testaceus, antennis pedibusque 
rufis ; prothorace obsolete punctato; elytris minus crebre subtiliter punctatis; coxis 
posterioribus obsolete punctatis. Long. 3, lat. 15 m.m. 
I am scarcely able to distinguish the sexes of this species. 
North America, (California, Utah). 405. 
642. Hydroporus latebrosus, Lec., M.C.—Ovalis, minus convexus, latiusculus, 
sine pubescentia, subnitidus, abdomine pectoreque nigris, supra fusco-testaceus, 
antennis pedibusque sordide rufis; elytris sparsim subtilius punctatis; prosterni 
processu. angusto; coxis posterioribus obsolete punctatis; abdomine seemento 
ultimo fere impunctato. Long. 33, lat. 2 m.m. 
The two individuals before me are I think male and female, though extremely 
similar to one another, The species is extremely close to H. vilis, but is larger and 
relatively very much broader. A specimen has been determined for me by Leconte, 
otherwise I should not Lave recognized the name from description. 
North America, (California). 406. 
643. Hydroporus hardyi, n. sp.—Ovalis, minus convexus, latiusculus, sine pubes- 
centia, subnitidus, abdomine pectoreque nigris, antennis pedibusque rufis ; elytris 
