4JS On Aquatic Carnivorous Coleoptera or Dytiscithe. 



I have seen only a single pair of this species ; the male has the breast and 

 hind body black beneath, while in the female the ventral segments are pale red ; the 

 sides of the metasternum, and the hind coxte except their posterior portion, are 

 rather coarsely punctured. The punctuation of its elytra consists of numerous 

 extremely fine punctures, evenly distributed as in Dytiscus confluens, but the larger 

 punctures which are sparingly but distinctly to be seen in the conunon species, are 

 reduced to three or four punctures at the base and along the suture in Hydroporus 

 pallidulus ; it possesses however a distinct discoidal line of fine impressed punctures 

 on each wing case. Aube says the female is opaque but in the individual before 

 me the elytra of that sex are about as shining as in the male, though just perceptibly 

 more finely punctured ; it is probable therefore that there are two forms of the 

 female in this species. 



Southern Europe, (Sicily and Andalusia) and Nortli Africa, (Algeria, Bune, ^Morocco). 194. 



423. Dytiscus confluens, Fab., Hydroporus conjluens, 31. C. — Ovalis, brevis, 

 subtus sat convexus, sine pubescentia, sat nitidus, subtus niger, supra testaceus, 

 elytris pallidis, sutura lineisque abbreviatis nigris, antennis pedibusque testaceis ; 

 elytris punctis parcis sat magnis, aliisque densis minimis ; coxis posterioribus crebre 

 fortiter punctatis, metasterno medio nitido fere impunctato. Long. 31, lat. 2 m.m. 



The external difference between the sexes seems to be extremelv slight. 



Middle and Southern Europe, North Africa, and Canary Isles. 193. 



I. 3G.— Genus CIIOSTONECTES. 



The rido-e on the inner face of the wing-case shows no lignla near the apex ; the 

 posterior portion of the epipleura is rather broad, and the genicular area is not 

 limited by a raised line ; the hind tibia shows on its infero-external face only the 

 serial punctures ; the posterior femur is slender and its outer angle rounded. The 

 mesosternal fork is not connected with the intercoxal jirocess of the metasternum. 



The four species * are found in Australia and Tasmania ; they are broad, robust, 

 compact insects. 



424. Chostonectes sharpi, (Wehncke), n. sp. — Ovalis, sat latus et convexus, 

 posterius subacuminatus, opacus, evidenter pubescens, fusco-nigei-, capite, thorace 



* In addition to these four species another but imperfectly known to me should be referred to Chostonectes, 

 viz., Hyphydrus johnsonii, Clk. (No. 1149 huj. op.), near No. 425; Australia. The position of the 

 fvjllowint' is doubtful, but may be iii Chostonectes, Hydroporus bakewelli, Clk. (No. 1343); Australia. 



