On Aquatic Carniworous Coleoptera or Dytiscide. 621 
952. Rhantus latitans, n. sp.—Ovalis, parum convexus, testaceus, vertice nigro- 
variegato, elytris nigro-irroratis, prothorace basi in medio breviter nigricante ; tarsis 
posterioribus articulo quarto extus lobato-producto. Long. 104, lat. 54 m.m. 
The male has the front tarsi moderately incrassate and a good deal compressed, 
and furnished beneath with rather small palettes, the marginal hairs but little 
developed, the claws are only moderately long and slender, the hinder one slightly 
shorter than the other; the middle feet are clothed beneath in a similar manner to 
the front feet, their claws are rather short, the thickened outer one being scarcely 
longer than the inner one, this, however, is more curved at its termination ; there is 
not the least trace of any strigosity in the middle of the apical part of the last 
ventral plate. 
This species is extremely closely allied to that preceding, with which it is always 
mixed in collections, the male has the front and middle claws much shorter, and 
the tarsal palettes rather smaller; the females are not so easily distinguished, but 
the constant black mark at the base of the thorax, and the smoother apical ventral 
segment, allow it to be recognized; there is also a slight difference in the form, 
which is generally narrower in front in the present species, and the produced lobe 
on the fourth joint of the hind tarsus is a little broader and shorter, and the longer 
of the two posterior claws is a little shorter and thicker. The female has generally 
a slight tendency towards a coarser reticulation near the outside of the elytra about 
the middle. Whether this be really a distinct species from the preceding is doubt- 
ful, for none of the characters except that of the male claws appear to be constant, 
and the females are always very difficult to distinguish. 
Europe, (Germany, Belgium), 899. 
953. Colymbetes consputus, Sturm, Rhantus consputus, M.C.—Ovalis, sat con- 
vexus, nitidus, testaceo-ferrugineus, vertice nigro-variegato, elytris nigro-irroratis, 
Long. 112, lat. 6¢ m.m. 
The male has the front tarsi much incrassate and comparatively little compressed, 
and furnished beneath with large palettes, the marginal hairs largely developed and 
with beautifully curled extremities, the claws are moderately long, and very nearly 
equal in length ; the middle tarsi are clothed beneath in a similar manner to the 
front feet, their claws are rather short and of about equal lengths, the outer 
however is thicker than the more curved inner one; the apical ventral segment is 
quite smooth along the middle ; the female has the outer portion of the elytra more 
coarsely reticulate especially about the middle, the apical ventral segment has the 
extremity quite smooth in the middle. 
The species is readily distinguished from D. exoletus and R. latitans, by its 
greater size, and by the greater development of the male tarsi. 
Ger » KOO, 
Europe, (Germany) 42 
