On Aquatic Carnworous Coleoptera or Dytiscide. 687 
D. festivus, and the yellow marks on the elytra are more distinctly formed into 
spots ; the two marks on the middle of the head are joined always to the black 
colour along the margin of the eye; the black bands on the thorax are large and 
definite, and connected by a spot on the middle; the suture of the elytra is black, 
and this black colour takes on three somewhat quadrate dilatations, while connect- 
ing the external angles of these quadrate marks are some other black marks, so 
that thus the yellow colour of the surface is broken up into isolated marks ; one of 
the most definite of these is a spot on the base at each side close to the scutellum. 
India. 980. 
1076. Hydaticus insignis, Wehncke, Stet. Ent. Zeit. XX XVII, p. 194.—Ovalis, 
sat latus et convexus, nitidus, subtus nigro-piceus, supra capite thorace elytrisque 
conspicue nigro flavoque pictis, antennis pedibusque anterioribus testaceis, pedibus 
posterioribus piceis. Long. 132, lat. 82, m.m. 
This differs from Sandracottus hunteri only in the markings of the upper surface ; 
the black colour has taken a greater extension, so that the yellow colour is divided 
into isolated spots. On the head the vertex is black, and there are two black spots 
on the middle placed at an angle to one another; the black colour of the front and 
hind margins of the thorax is scarcely connected by a central spot. On the wing- 
eases there are two rather small basal spots yellow, and a large humeral yellow 
mark in which is a black dash; the black colour behind these basal marks forms a 
very irregular broad band, which is in front but little distant from the scutellum, 
while at the sides it is only just in front of the middle; behind this black band is 
a broad, irregular yellow band, interrupted at the suture, and divided into 
two large marks by a slender longitudinal prolongation from the black band 
behind it, this latter is broad and placed some distance before the extremity ; 
the black colour extending along the suture is a little dilated just before the 
extremity, and is nearly connected with a small black mark placed very near the 
apex. 
I have seen but a single female individual, and am very doubtful whether it will 
prove to be a distinct species from the variable Sandracottus hunteri. 
Philippine Islands. _ 982. 
1077. Hydaticus bakewelli, Clk., M.C.—Ovalis, parum latus et convexus, leeviga- 
tus, pernitidus, subtus niger, supra capite, thorace elytrisque nigro flavoque pictis, 
antennis pedibusque anterioribus testaceis, pedibus posterioribus nigricantibus, 
femoribus dilutioribus. Lone. 143, lat. 8 m.m. 
In this species the vertex is black, and the black mark on the middle of the head 
is connected at the sides to the black along the margin of the eye; the black band 
