On Aquatic Carnivorous Coleoptera or Dytiscide. 447 
The only individual I have seen has the front and middle tarsi slender and is 
perhaps a female. 
City of Guatemala, (G. C. Champion, 1879). 1146. 
527. Hydroporus mexicanus, n. sp.—Ovalis, latiusculus, convexus, fere opacus, 
niger, prothorace elytrisque plus minusve obscure sanguineo-maculatis, antennis 
obscure rufis, versus apicem fusco-maculatis, pedibus nigris, anterioribus vix rufes- 
centibus ; capite prothoraceque dense subtiliter sed distincte punctatis ; hoc basi 
utrinque ruguloso, lateribus oblique subrectis, angulis posterioribus rotundato- 
obtusis; elytris omnium densissime vix conspicue punctulatis, seriebus suturali 
allisque externis minus distinctis valde abbreviatis punctorum impressorum ; 
corpore 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, M.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 nigro ; 
corpore supra vix perspicue punctulato, subtus fortiter punctato. Long. 43, 
lat. 23 m.m. 
Mas, tarsis anticis et intermediis latioribus, anterioribus unguiculis longioribus 
eequalibus ; abdomine nigro, apice medio ferrugineo. 
Fem., 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. 
