346 On Aquatic Carnivorous Coleoptera or Dytiscida. 
GROUP 2. 
244, Hydroporus apicatus, Clk., M.C.—Brevis, latus, ovalis, posterius valde 
acuminatus, castaneo-testaceus, nitidus, glaber; prothorace basi utrinque striola 
subtili ; elytris crebre subtiliter sed distincte punctatis, Long. 1%, lat. 1 m.m. 
Head very broad, impunctate, clypeus not margined. Thorax almost impunctate, 
with the hind angles indistinct but a little obtuse. Elytra with fine punctures, 
which become very indistinct at the sides and extremity. Hind coxze with some 
moderately coarse punctures, middle of breast quite impunctate. 
T am not quite sure as to the locality of this peculiar little species, but I believe it is St. Domingo. I 
have only seen two individuals of it. 75. 
245. Bidessus borrei, n. sp.—Brevis, latus, ovalis, valde convexus, posterius 
acuminatus, nitidus, glaber, castaneo-testaceus, elytris obscurioribus ; prothorace 
basi utrinque stria subtili, elytris sat crebre subtiliter punctatis ; coxis posterioribus 
7 
fere impunctatis. Long. 13 m.m., lat. $ mm. 
This species seems closely allied to Hydroporus apicatus, but it appears to me to 
have the prosternal process rather broader, it is also considerably smaller, narrower, 
and more convex, and the elytra are more obscure in colour. 
IT have seen only a single individual which is in the collection of the Brussels Museum. It is I believe 
from Pernambuco, and bears a label, “fuscipennis, Chev.” 76. 
246. Hyphydrus acuminatus, Steinheil, Atti. Soc. Ital. Sci. Nat. XII, p. 249.— 
Brevis, latus, ovalis, convexus, posterius acuminatus, nitidus, glaber, ferrugineus, 
elytris obscurioribus, prothorace basi utrinque stria subtili; elytris sat erebre sub- 
tiliter punctatis ; coxis posterioribus, sparsim distincte punctatis. Long. 13, lat. 
1 m.m. 
Closely allied to Hydroporus apicatus and Bidessus borrei, (Nos. 244 and 245), 
but has the antennz a good deal thinner than in H. apicatus, and is rather larger 
and a good deal broader than Bidessus borrei, and has the hind coxe distinctly 
punctured. 
Tam indebted to M. Steinheil for an authentic example of this interesting species, 
Buenos Ayres. 77. 
Group 3. 
247. Hydroporus bicarinatus, Clairville, M.C.—Breviter ovalis, subtus convexus, 
sine pubescentia, nigricans, thorace medio rufescente, elytris testaceis, sutura 
fasclisque nigris ; supra dense subtiliter sed evidenter, subtus fortiter profundeque 
