446 Mr. David Sharp on the 



autennis pedibusque testaceis ; corpore supra subtiliter punctulato, 

 tliorace versus angiilos posteriores singulis brevissimis impressis ; 

 elytris striis argutis sex, externa posterius parum abbreviata, 

 striaque submarginali modice elongata. Long. 6 mm., lat. 3 mm. 



The male has the front and middle tarsi a good deal 

 dilated, and in the female the sculpture at the hind 

 angles of the thorax is coarser. The species belongs to 

 Group 10, and is not closely allied to any other. The 

 only two individuals found are immature ; one was 

 obtained in Kiishiu {Mr. Wada), the other has no locality 

 recorded. 



Rhantus erraticus. 



Ovalis, subdepressus, subopacus, subtus niger, supra testaceus, 

 capite nigro-variegato, prothorace in medio plaga transversa nigi-a, 

 elytris crebrerrime nigi'o-irroratis, antennis pedibusque aute- 

 rioribus testaceis, femoribus basi nigricante, pedibus intermediis 

 nigris geniculis tarsisque rufis ; corpore superne densissime minus 

 subtiliter rugoso. Long. 13 mm., lat. 6 mm. 



This species resembles greatly a large flat Colymhetes 

 pulrerosus, but it has the peculiarity of being dull above 

 owing to a much less obsolete sculpture than exists in 

 the males of other species of this genus. The male 

 has the front and middle tarsi a good deal incrassate, 

 and the claws of the anterior feet are elongate and 

 simple. The female is unknown. 



A single example occurred at Yumoto, August 24th, 

 1881. 



Dytiscus marginaUs. 



The occurrence of this species in Japan, which was 

 previously somewhat doubtful, has been certified by the 

 capture of one female example at Chiuzenji and another 

 at Sapporo. 



Dytiscus sharpi. 



Dytiscus sharpi, Wehncke, Stett. Ent. Zeit., 1875, 

 p. 500. 



This species was met with, though only in four or five 

 examples, at Uyeno, in Tokio, December, 1880. The 

 female before me is of much interest, as, though the 

 peculiar sulcation seen in so many of the species of the 

 genus Dytiscus is not present, yet there are on the 

 external part of the elytra three or four slight grooves 

 or striae, being, as it were, the rudimentary condition or 



