On Aquatic Carnivorous Coleoptera or Dytiscide. 485 
sparsim subtilissime punctatis; prosterni processu latiusculo ; coxis posterioribus 
subtiliter punctatis; abdomine segmento ultimo confertim subtiliter punctato. 
Long. 4, lat. 24 m.m. 
I have seen only one individual of this, the largest species of the group, it is 
rather larger than our European H. lituratus (No. 569). 
North America, (California, found by Mr. Hardy). 407. 
644. Hydroporus belfragei, n. sp. —Oblongo-ovalis, depressus, sine pubescentia, 
subnitidus, ferrugineus, abdomine pectoreque nigris, elytris ferrugineo-testaceis ; 
ubique parce obsoleteque punctatus, Long. 3, lat. 14 m.m. 
I have seen but a single individual of this distinct species, though allied to H. 
vilis (No. 641), it is more depressed, brighter coloured, and has the prosternal process 
rather more elongate, and distinctly carinate along the middle near the apex. 
North America, (Texas, sent by Belfrage). 408. 
Grovr 9. 
645. Hydroporus difformis, Lec., M.C.—Oblongo-ovalis, elongatus, sine pubes- 
centia, sat nitidus, piceus, supra dilutior, antennis pedibusque rufis; elytris crebre 
parum subtiliter, distincte punctatis, punctis apicem versus paulo crebrioribus ; 
corpore subtus nitido, sublzevi, abdominis lateribus strigulosis. Long. 53, lat. 3 m.m-. 
I have seen only a single individual of this large and remarkable species, which 
by its appearance calls to mind the estriate Copelati ; the specimen is probably a 
female. 
The species seems to be very peculiar, and will no doubt prove generically distinct, 
meanwhile it appears best placed near H. oblongus, from which it differs by the 
rather widely separated middle coxe, the very large prosternal process, which is 
elevated at the sides and along the middle, and terminates in front as a strongly 
elevated projection ; the metasternum is broadly but obscurely depressed in the. 
middle in front ; and the coxal lines are but little turned outwards near the extremity. 
The highly developed coxal lobe, with very rounded extremity quite protects the 
articular cavity, as in H. oblongus. 
North America, (Georgia, Boston). 268. 
646. Hydroporus oblongus, Steph., M.C.—Oblongo-ovalis, eclongatus, sine 
pubescentia, nitidus, niger, supra fusco-castaneus, antennis pedibusque rufescentibus, 
elytris sparsim distincte, apicem versus crebrius punctatis; corpore subtus fere 
impunctato. Long. 5, lat. 25 m.m. 
3 R 2 
