Pselaphidce of Japan. 309 



abdominal basal segment is at the base only moderately 

 distant from the side. 



The sex of the unique individual is uncertain. 



Yuyama, May 12th, 1881. 



Batrisus oscillator, n. s. 



Eobustus, densius pubescens, subtiliter punctatus, 

 subopacus, rufescens ; prothorace medio tenuiter canali- 

 cular, lateribus longitudinaliter impressis ; elytris 

 crebrius subtiliter punctulatis, humeris haud denticu- 

 latis, intra humeros depressis sed vix plicatis, basi fere 

 absque foveolis ; abdomine segmento basali sequentibus 

 duobus sequali ; tibiis posticis calcari apicali perbrevi. 

 Long. 2£ mm. 



Mas, antennis articulo basali inflato, faciei anterioris 

 angulo externo producto, capite supra antennas valde 

 prominulo, inter eas profunde depresso, sub antennas 

 longius penicillato ; clypeo verticali, carina elongata, 

 transversa, in medio processu libero parvo armata ; 

 abdomine segmento ultimo ventrali late impresso. Fern, 

 incog. 



This species is remarkable from the finer and close 

 punctuation of the surface ; the head is without any 

 coarse punctuation, even on the greatly elevated antennal 

 protuberances ; it is allied by the structure of the head 

 and antennse to B. vestitus, from which it is readily 

 distinguished by the very stout apical spur of the hind 

 tibiae. 



Two specimens found with a Formica under a stone on 

 the Mikuni toge, 22nd Sept., 1881. 



V. Surface of body glabrous. B. politus and B. concolor. 



The above character distinguishes the two species 

 from all the others at a glance ; they have also a peculiar 

 formation of the head, the vertex being truncate behind, 

 and separated from the neck by an abrupt, very short 

 constriction or incision ; there is no spur to the hind 

 tibiae. In other respects the two species are not closely 

 allied. 



