48 Mr. David Sharp on the 
stones on MItsnyama, Nagasaki, and fi-om ponds at Osaka. 
This species has been identified by Mr. Lewis, by com- 
parison with specimens in the British Museum. 
6. Hydaticus vittatus, Fab. Very common in Kushiu 
and Nipon. It is quite probable that several closely allied 
species are confounded under the name of vittatus. We 
must wait, however, till series of individuals from various 
localities can be examined before deciding this point. 
7. Hydaticus rufulus, Aube. Nagasaki and Hiogo. 
This species is united in the Munich catalogue with our 
European H. Leander, but I entertain doubts as to the 
correctness of this. 
8. Hydaticus grammicus, Germ. Nagasaki. 
9. Hydaticus japonicus, n. sp. Breviter ovatus, con- 
vexus, capite prothoraceque testaceis, nigro signatis, elytris 
nigricantibus flavo-irroratis ; subtus nigro-piceus, protho- 
racis lateribus, prosterno, pedibus quatuor anticis epi- 
pleurarumque basi testaceis, pedibus posterioribus nigris 
femoribus flavo-ornatis. Long, of — 6^ lin. ; lat. 3| — 
4 lin. 
Mas, tarsis anticis et intermediis dilatatis. 
This species will be best described by a comparison 
with H. cinereus, to which it is closely allied. The 
colouring of the upper surface is just the same as in cinereus, 
but beneath, /a^ow/cMs is very much darker, and the form 
oi japonicus is Very much shorter than that of cinereus. 
The female differs from the male by its simple tarsi, by 
possessing a few obscure lines or strigje near the sides of 
the thorax, and also by the yellow band of the middle of 
the thorax being narrower than in the other sex. 
Very abimdant in the fens of Osaka and the ponds of 
Hiogo. 
10. Colymhetes pulverosus, Steph. Widely distributed 
and abundant. 
11. Ayabus conspicuus, n. sp. Latior, ovatiis, con- 
vexus, supra subtiliter reticulatus, capite prothoraceque 
nigi'o-a^neis, illo maculis duabus rufis, elytris fuscis, mar- 
ginibus dilutioribus ; subtus subtiliter strigosulus, niger. 
Long. 5^ lin. ; lat. S-g lin. 
Mas, unguiculis anticis longitudine suba3qualibus, an- 
