Pselaphidce of Japan. 295 



Ctenistes. 



This genus and its allies offer, even at present, great 

 practical difficulties in their limitation, each of them 

 showing much variety in structure of the forms included 

 in them. The Japanese species, even after the separa- 

 tion of those assigned to Poroderus, are heterogeneous, 

 C. mimeticus being apparently a typical Ctenistes, while 

 C. oculatus is very isolated ; and C. discedens approaches 

 in some respects to the North American forms of the 

 genus ; C. breviceps again belonging apparently to the 

 subgenus Sognorus of Eeitter. The species seem to 

 be of great rarity, with the exception perhaps of C. 

 breviceps. 



Ctenistes mimeticus, n. s. 



2 . Kufus, nitidus, sat crebre setulosus ; antennis 

 minus elongatis, apicem versus incrassatis, articulo 

 septimo quam contiguis paulo longiore, undecimo praece- 

 dentibus duobus simul sumtis paulo longiore. Long. 

 2£ mm. N.B. feminse C. armati fere omnino similis, notis 

 generis fere tantum differt. 



Ctenistes medius, ? ?, Sharp, Trans. Ent. Soc. Lond., 

 1874, p. 112. 



This insect resembles excessively the female of C. 

 armatus, but differs therefrom by the 2nd joint of the 

 maxillary palpi being armed with a seta, and by the 

 posterior trochanters being shorter and not clavate. 



A specimen was found in the Nagasaki district, April 

 12th, 1881 ; and the insect I queried as being possibly 

 the female of C. medius is also an individual of this 

 species. The two specimens agree entirely in all 

 characters of importance, and are, I presume from the 

 structure of their antennse, females. 



Ctenistes oculatus, Sharp. 



Sharp, Trans. Ent. Soc. Lond., 1874, p. 110. 



This remarkable insect is still unique, and is very 

 distinct from any other Ctenistes known to me; the 

 tenuity of its tibiae is very remarkable. 



