PVater Beetles of Japan. 51 
variable yellow marks. The lateral laciniae of the meta- 
steriium are extremely narrow. 
Three examples of this interesting species have been 
submitted to me by Mr. Lewis, without particular locality 
being indicated. 
15. Copelatus , spec. ? There are two specimens of this 
genus in the collection, one male (from Osaka), one female 
(from Nagasaki) ; I have been unable to satisfy myself 
that they are certainly the same species, and I do not there- 
fore describe them. Mr. Lewis feels sure they are distinct 
species, and I think it very likely to prove so. 
16. Ilybius apicalis, n. sp. Oblongo-ovalis, supra 
feneus, margine pallescente ante apicem trihamato ; subtus 
ferrugineus; metasterni laciniis perangustis. Long. 4^ 
lin. Tlat. 2^ lin. 
This species resembles in foraci 7. fuliginosus, but is 
readily to be distinguished l^y the band of the elytra, 
which has a large treble spot attached to it at the ex- 
tremity, and by the very different shape of the side wings 
of the metasternum. The upper surface is brassy, with 
the front of the head, the sides of the thorax and elytra 
yellowish; the pale band of the elytra is divided in its 
posterior part by a darker line, and a little behind the 
middle there is close to the band a short pale dash ; the 
sculpture of the upper siu'face is very fine and dense. 
The under surface is of a rusty colour, the antennas and 
legs reddish-yellow. The anterior margin of the hind 
coxre is very much extended forwards, more so even than 
\n fenestratus. 
The structure of the claws in the male does not differ 
from that of the female ; the outer claw of the hind foot 
is slender and but little curved. 
Ponds in sandy districts. Hiogo and Simabara. Rare. 
17. Hydrocanthus politus, n. sp. Ovalis, nitidus, 
laevis, testaceus, elytris fuscis, testaceo-maculatis ; pro- 
sterno pectorisque parte elevata fortiter punctatis. Long, 
li lin. 
Entirely shining yellow, with the exception of the ely- 
tra, which are blackish, but largely marked with yellow ; 
these markings consist of two very large yellow spots at 
the base, and a transverse band placed a little behind the 
middle and interrupted at the suture, the extremity also 
E 2 
