722 On Aquatic Carnivorous Coleoptera or Dytiscide. 
cases is more definitely limited in its area than in the preceding form, the sutural 
portion being quite smooth except on the basal one-fourth or one-fifth, and there 
is also a much larger apical portion free from sculpture ; the thoracic sculpture is 
the same as in the Mauritian form, but that on the head is but slight, there being 
only some scratches in the neighbourhood of the eyes. In this therefore the chief 
difference from. the Mauritian form is that the sculpture is more concentrated on 
the middle portions of the body : it is possible that this is the insect Klug described 
as Cybister vulneratus. 
The males of these forms can scarcely be distinguished inter se. The Madagascar 
individuals are usually rather broader than the African ones, while the Mauritian 
examples are rather broader and shorter, and the Arabian individuals are rather 
narrower, and approach nearer to a truly elliptical form than do any of the others. 
The species varies a good deal in size and colour, independently of the local 
variations, and the size of the patch of sexual hairs on the male middle tarsus like- 
wise varies somewhat: as does also the supplementary obsolete claw of the female 
hind tarsus ; I have indeed an individual of this sex from Lake Nyassa in which no 
trace of this claw can be detected. 
The species is widely distributed in Africa; in the North it reaches to the coasts of the South of Europe, 
but is there very rare, while in the South it extends to Lake Nyassa; it is also found in Madagascar, 
Mauritius, and Arabia (Hedjaz, Dr. C. Millingen). 1063. 
1134, Cybister insignis, n. sp.—Ovalis, anterius angustatus, nigricans, prothorace 
ad latera vage ferrugineo, pedibus anterioribus et intermediis, (antennisque ?) rufis ; 
pedibus posterioribus piceis, tarsis fere nigris. Mas, Long. 26, lat. 132 mm. Fem., 
Long. 26, lat. 12 m.m. 
The male of this species has the front tarsi large, attaining 8 m.m. in the trans- 
verse direction ; the intermediate tarsi, have on the basal joint beneath, a very large 
and broad patch of short sexual pubescence, and there is algo a large patch onthe follow- 
ing joint, the claws are elongate and nearly straight, the anterior one being thick, 
and but little longer than the other. The female has the occiput, the thorax and 
the elytra covered with deep, coarse scratches; the sculpture on the elytra consists 
of deep coarse elongate scratches which extend about four-fifths of the length of 
the elytra, but are represented near the suture by only a few scratches, near the 
lateral margin there is a kind of plica or fold, and the sculpture is abruptly termi- 
nated at this fold, so that within the lateral margin there appears to be, as it were, 
a smooth groove, which commences in an indefinite manner a little behind the 
shoulder, gets broader as it goes backwards, and extends as far backwards as the 
scratches do ; the epipleurse of the elytra are broad, flattened and obliquely perpen- 
dicular a little distance behind the shoulder, and the supplementary claw of the 
