374 On Aquatic Carnivorous Colcoptera or Dytiscidce. 



332. Darwinbydrus solidus, n. sp. — Latus, sat convexus, fere opacus, sine pubes- 

 centia, ferrugineus, supra fusco-testaceus, fortiter punctatus, elytris costis tribus 

 elongatis elevatis. Long. 3|, lat. 2i m.m. 



Head broad and short, rather ooarsely punctured, the clypeus completel}^ rounded 

 in front and finely margined. Thorax very short, very closely adapted to the base 

 of the elytra, the lateral margins strongly elevated, moderately coarsely punctured. 

 Elytra with large distinct punctures rather closely placed, and each with three 

 elevated ribs, the inner one placed at a considerable distance from the suture, the 

 outer one rather near to the pleural margin and curved so that it joins the inner 

 line close to the extremity of the elytra, the middle rib does not join the others. 

 Coxae coarsely, moderately closely, punctured. 



I have seen only one individual, of whose sex I feel doubtful. 



South Africa, (Cape Town). 188. 



I. 30.— Genus HYPHYDRUS. 



Tntercoxal process of metasternum obscurely but decidedly connected with the 

 mesosternum : its extremity being turned upwards so that it rises into the mesoster- 

 nal fork. Terminal joint of the front tarsus very obscure and but little exserted 

 from the third joint. 



This genus consists at present of about twenty-five species* ; they are very simi- 

 lar to one another, and their determination is not easy ; no doubt many more species 

 exist undescribed and an attempt to discriminate by means of a table the species 

 here described would not be likely to prove of use. The punctuation of the wing- 

 cases is very useful for distinguishing many of the species ; it consists often of a 

 double punctuation viz, (o) coarse and few, (6), fine and numerous, punctures; the com- 

 parative development of these two forms of punctuation .should be noticed. The 

 distinctive characters of the sexes are also very important aids. 



The species do not occur in the Xew World. 



* In addition to these the following descriptions probably refer to species of this genus. Hydroporus 

 tifasciatus, Macl. (No. 1345 huj. op.) ? = No. 358 ; Australia. — Hydroporus coquereli, Fairm. (No. 1355), ? 

 = No. 34G; Madagascar. — Hyphydrus caffer, Boh. (No. 1460) ; CafTraria. — Hyphydrus circumflexus, Klug, 

 (No. 1462), near No. 345; East Africa.— Hyj.hydi-us illigeri, Perrd. (No. 1465)1 = No. 358; New 

 Caledonia. — Hyphydrus higubris, de Borre. (No. 1467) ; Sinai. — Hyphydrus maculatus, Bab. (No. 1468) ; ? 

 South America. The genus to which the following two descriptions should be referred is doubtful, 

 Hyphydrus austro-caledonicus, Perrd. (No 1459) ; New Caledonia. — Pachytes elegans, Mont. (No. 1499) ; 

 New Caledonia. 



