493 On Aquatic Carnivorous Coleoptera or Dytiscide. 
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 cox except their posterior portion, are 
rather coarsely punctured. The punctuation of its elytra consists of numerous 
extremely fine punctures, evenly distributed asin Dytiscus confluens, but the larger 
punctures which are sparingly but distinctly to be seen in the common 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. Aubé 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 North Africa, (Algeria, Bone, Morocco). 194. 
423. Dytiseus confluens, Fab., Hydroporus confluens, M.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. 33, lat. 2 m.m. 
The external difference between the sexes seems to be extremely slight. 
Middle and Southern Europe, North Africa, and Canary Isles. 193. 
T. 36.—Genus CHOSTONECLES:. 
The ridge on the inner face of the wing-case shows no ligula 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 process 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-niger, capite, thorace 
*Tn addition to these four speciesanother 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 
following is doubtful, but may be in Chostonectes, Hydroporus bakewelli, Clk. (No. 1343); Australia. 
