548 On Aquatic Carnworous Coleoptera or Dytiscide. 
angulis posterioribus bene acutis; elytris crebrius vbsolete reticulatis, punctis 
subseriatis minutis; thorace margine laterali nullo; prosterni processu lato, apice 
acuminato ; lineis coxalibus nullis. Long. 8, lat. 4$ m.m. 
The male has the basal joints of the front and middle tarsi distinctly incrassate, 
and furnished beneath with rather short glandular hairs, and in the same sex there 
are three or four striz on each side of the apical ventral segment. 
South America, (Peru). 825. 
I. 51.—Genus AGA BINUS. 
Coxal lines deeply impressed, and very little sinuate so as to be subparallel, 
the coxal border continued forwards to the posterior border of the metasternum. | 
The genus consists of a Californian species. 
777. Colymbetes glabrellus, Motsch., M.C.—Ovalis, sat convexus, pernitidus 
fere levigatus, niger, antennis pedibusque rufis vel piceis; thorace cum elytris 
continuo, angulis posterioribus subrectis; elytris punctis seriatis minutis ; tarsis 
posterioribus gracilibus ; lineis coxalibus subparallelis, versus apicem nullo modo 
extrorsum abductis. Long. 43, lat. 32 m.m. 
The male characters are very slight, there is scarcely any incrassation of the front 
and middle tarsi, and their two basal joints only are furnished beneath with small 
patches of glandular hairs. 
North America, (California), 833. 
I. 52.—Genus PLATAMBUS. 
Epipleurze behind the middle comparatively broad. 
The three species are found in the European and Japanese regions. 
778. Dytiscus maculatus, Linn,, Agabus maculatus, M.C.—Ovalis, sat convexus, 
ferrugineus, vertice, prothorace anterius et posterius elytrisque infuscatis, his 
margine laterali signaturisque plus minusve extensis testaceis ; prothorace haud 
brevi, margine laterali tenui, angulis posterioribus acutis ; elytris ad basin seepius 
