434 On Aquatic Carnivorous Coleoptera or Dytiscide. 
490. Hydroporus ceresyi, Aubé, M.C.—Ovalis, angustulus, elytris dense 
breviterque pubescentibus, fere opacus ; subtus niger, supra testaceus, prothorace vel 
concolore vel indistincte nigro-notato, elytris sutura lineisque haud confluentibus 
nigris; prothorace lateribus obliquis, postice latiore angulis posterioribus acutis ; 
corpore dense subtilissime punctulato. Long. 4%, lat. 2 m.m. 
The male has the front and middle tarsi a good deal broader than the female. 
The lines on the elytra are often much diminished and are sometimes nearly 
absent: in other specimens the lines are broader, and then become connected 
together here and there by spot-like dilatations. 
South Europe and North Africa ; (South France, Sardinia, Spain, Mogador, Egypt). 261. 
491. Deronectes suffusus, n. sp.—Ovalis, haud nitidus, subtus niger, supra ex 
testaceo nigroque coloratus, elytris lineis valde confluentibus nigris ; corpore dense 
subtilissime punctulato, sculptura prothoracis disci parciore et minus subtili ; 
subtus subtilissime reticulato. Long. 42, lat. 2¢ m.m. 
Very closely allied to Deronectes prosternalis, but not so acuminate behind, with 
the sculpture of the prothorax not so fine and even, and with the carina of the 
prosternum less elevated in front. 
I have seen only a single individual, in bad condition. 
North America, (Coll. Bonvouloir). 270. 
492. Deronectes prosternalis, n. sp.—Ovalis, breviter sed evidenter pubescens, 
haud nitidus, subtus niger, supra ex testaceo nigroque coloratus, elytris lineis valde 
confluentibus nigris; corpore dense subtilissime punctulato, subtus subtilissime 
reticulato ; prosterno ante coxas evidenter carinato-elevato, carina anterius abrupta. 
Long. 44, lat, 2¢ m.m. 
I see scarcely any external sexual distinctions. 
This species is extremely similar to the European Dytiscus eriseostriatus, (No. 
493), but is distinguished by the considerably stronger carination of the prosternum 
in front of the anterior coxee. I have examined about a dozen individuals to assure 
myself of the validity of this character. 
North America. 269. 
493. Dytiscus griseostriatus, de Geer, Hydroporus griseostriatus, M. C.—Ovalis, 
angustulus, evidenter pubescens, sub-opacus, subtus niger, supra testaceus, capite 
utrinque, prothoracis signaturis elytrisque lineis septem elongatis nigris; supra 
