On Aquatic Carnworous Coleoptera or Dytiscide. 665 
1938. Colymbetes pulcher, Clk., M.C. —Ovalis, fere angustus,subtus rufo-obscurus, 
supra rufo-testaceus, capite vertice plagaque transversa inter oculos, prothorace 
basi margineque anteriore in medio plus minusve nigricantibus, elytris creberrime 
nigro-irroratis, irrorationibus versus suturam coalescentibus ; tarsorum posticorum 
marginibus posterioribus parum longe ciliatis. Long. 11, lat. 6 m.m. 
In the male the fringing hairs round the heel of the front tarsus are moderately 
well developed, and the basal palettes are distinctly a little larger than the others. 
This species is of rather more parallel and narrower form than most of its allies, 
and may be distinguished by the peculiarity that not only is the vertex black, but 
there is also a patch of dark colour between the eyes. The ciliation of the hind 
tarsi does not differ much from that of Hydaticus servillianus. I have seen but 
few specimens, and they vary somewhat in size, and in the extent of the black 
colour on the anterior margin of the thorax ; this is never very conspicuous, and 
seems to be less so in the male than in the female. In some individuals of this 
latter sex, some obsolete rugze or impressions may be observed on the lateral parts 
of the thorax, but im others they are quite absent. 
Australia, (Brisbane ; Clarence River ; South Australia). 1007. 
1039. Hydaticus servillianus, Aube, M.C.—Ovalis, elongatus, rufo-testaceus, 
vertice nigro, elytris creberrime nigro-irroratis, irrorationibus versus suturam 
coalescentibus, pectore abdomineque picescentibus ; tarsorum posticorum marginibus 
posterioribus haud longe ciliatis. Long. 12, lat. 62 m.m. 
In the male the fringing hairs round the heel of the front tarsus are largely 
developed and conspicuous, and there is a good deal of variety in the size of the 
palettes of the undersurface, one of the two at the base being conspicuously large ; 
the female has some irregular very short impressions scattered on the lateral parts 
of the thorax. 
The species much resembles some of the varieties of Dytiscus leander (No. 1032), 
but is larger in size and more elongate in form; the male can be readily dis- 
tinguished from D. leander by the fringing hairs of the front feet, and the female 
by the presence of thoracic impressions ; the ciliation of the hind margins of the 
posterior tarsi is the same as in D. leander. 
I have seen but few specimens of this species, it seerns to be rather variable in 
size, and in the amount of condensation of the black irrorations on the wing-cases, 
and sometimes the thorax appears black at the base in the middle. ihe thoracic 
sculpture of the females seems also to be somewhat variable. 
South Africa, (Caffraria, Cape of Good Hope). 1006. 
1040. Hydaticus palhatus, Aube, M.C.—Oblongo-ovalis, robustus, sat convexus, 
subtus piceus, prosterno rufo, supra capite thoraceque rufo-testaceis, illo vertice 
