450 Mr. David Sharp on the 



OguraLake, July 1st, one female; Tokio {Mr. Tanaka), 

 one male. 



HYDEOPHILID^. 



Hydrocharis libera. 



Ovalis, convexa, nigra, antennarum basi testaceo ; dense sub- 

 tiliter punctate, elytris seriebus punctoruni impressis conspicuis ; 

 prosterno posteriiis mutico, metasterno posterius apice spinam 

 brevem in medio formante ; femoribus posterioribus fei-e impunc- 

 tatis. Long. 19 mm., lat. 10 mm. 



This species is excessively similar to the European 

 H. caraboides, auct., but is readily distinguished by the 

 middle of the prosternum being without spine, by the 

 impunctate femora, and by the projection of the meta- 

 sternum in the middle behind forming a longer free 

 spine. This latter character will distinguish the species 

 from H. affinis, besides the colour differences in the legs, 

 palpi, and inflexed margin of the wing-cases. 



Five examples were found at Hakodate towards the 

 end of September, 1880. 



Hydrocharis affinis. 



Hydrocharis affijiis, Sharp, Trans. Ent. Soc. Lond., 



1873, p. 58. 

 H.Jlavipes, var.. Sharp, op. cit., p. 59 (nee Steph.). 



Mr. Lewis has now secured a series of about a dozen 

 examples of this species. Though very closely allied to 

 the European H. JlavijJes, I think it will prove distinct, 

 the size being very much greater, the thorax more 

 transverse, the striation on the wing-cases always dis- 

 tinct, and the middle of the prosternum rather differently 

 formed, being shorter in proportion and less produced 

 behind, more obtusely rounded in front. The specimen 

 recorded as being possibly a variety of H. Jiavijjes is, I 

 am satisfied, now that I have had an opportunity of 

 comparing it with a series of H. affinis, onl}^ a small, ill- 

 developed, immature individual of that species. 



Found in Ogura lake, near Nara, towards the end of 

 June, and at Niigata in September ; I have also a speci- 

 men of the species from Castlenau's collection labelled 

 Shanghai. 



