On Aquatic Caraivorous Coleoptera or Dytiscidoe. 447 



The only individual I have seen has the front and middle tarsi slender and is 

 jjerhaps a female. 



City of Guatemala, (G. C. Champion, 1S79). 1146. 



527. Hydroporus mexicanus, n. sp. — Ovalis, latiusculus, convexus, fere opacus, 

 niger, prothorace elytrisque jjIus miuusve obscure sanguineo-maculatis, antennis 

 obscure rufis, versus apicem fusco-maculatis, pedibus nigris, anterioribus vix rufes- 

 centibus ; capita protlioraceque dense subtiliter sed distincte punctatis ; hoc basi 

 utrinque ruguloso, lateribus oblique subrectis, angulis posterioribus rotundato- 

 obtusis ; elytris omnium densissime vix conspicue punctulatis, seriebus suturali 

 aliisque externis minus distinctis valde abbreviatis punctorum impressorum ; 

 corjiore subtus opaco, coxis posterioribus rugulosis. Long. 5, lat. 3 m.m. 



This species varies a good deal in colour, in some specimens the dark red spots 

 have a considerable extension, while sometimes they are nearly absent. The male 

 differs but little from the female, but the claws of its front tarsi are more elongate. 



Hydroporus Roffi, Clk., is an allied species with a more finely punctured thorax. 



Mexico. 457. 



B. 



528. Dytiscus halensis, Fab., Hydroporus halensis, 31. C. — Ovalis, sat latus, sub- 

 opacus, dense brevissime pubescens, supra testaceus, prothorace in medio nigro- 

 signato, elytris lineis sex maculisque interjectis nigris; antennis pedibusque 

 testaceis, illis articulis versus apicem his tarsis fuscescentibus ; pectore nigi'o ; 

 corpore supra vix perspicue punctulato, subtus fortiter punctato. Long. 4^, 

 lat. 2h m.m. 



2Ias, tarsis anticis et intermediis latioribus, anterioribus unguiculis longioribus 

 aequalibus ; abdomine nigro, apice medio ferrugineo. 



Fern., abdomine ferrugineo. 



This is a very variable species, and the variations occur in accordance with 

 locality : the sculpture of the upper and undersurfaces varies a good deal as does 

 also the colour and markings. A remarkable variety is found in Corsica, in it the 

 black marks on the head and thorax are very distinct, and those on the elytra form 

 blotches rather than lines, and the male has a small sharp tooth on the inner claw 

 of the front tarsus. A very large race is found in Sardinia. And in Algeria there 

 occurs another remarkable form in which the thorax is entirely black except at the 

 sides. 



Europe. Britain, Belgium, France, Germany, Turkey, Italy, Spain, Egypt, Algeria, Sardinia, 

 Corsica ; Madeira sec. Wollaston : (said to have been found in Lapland by Sanmark). 222. 



