393 



male collected at Corvallis, Oregon, June 30, probably 1907 

 or 8 (J. C. Bridwell). 



This has since remained in my collection unidentified, 

 the peculiar structure of the mandibles having been un- 

 described. The mandibles are rather elongate and slender 

 and bidentate at apex, the lower tooth being much longer 

 than the upper. When the mandibles are closed, doubtless 

 the huge median tooth is concealed. This is sub-triangular, 

 a little recurved, acute at apex, and a little longer than its 

 <listance from the upper (or inner) apical tooth. 



In Myrmosa unlcolor the mandible is tridentate at the apex 

 and the inner broad triangular tooth is much nearer the apex 

 of the mandible. 



31. Odynerus pseudochkomus Perkins. 



Occasionally this species has the angles of the propo- 

 deum reddish and a large round spot on either side of the 

 second tergite. 



The male varies also with clypeus with an encircling 

 jellow margin as well as the red spots on the second tergite. 

 Either of these variations may exist independent of the other. 



Pseudochronius may be distinguished from lelodemas by 

 the smooth lateral area on the dorsal face of the propodeum. 

 This species employs the pupal chambers of Anobiid beetles 

 from which the beetles have emerged as well as the pith 

 cavities of the twigs. In either case the cavity containing the 

 cells is closed by a mud plug at the entrance some distance 

 away from the last cell. Two or three cells fill the Anobiid 

 pupal chamber while I have seen nests of a dozen cells in pith 

 cavities. 



32. Two New E'earctic Species or Hypomiscophus 



OOCKERELL FROM THE PaCIFIC CoAST. 



Hypomiscophus Cockerell and Miscophirms Ashmead are 

 synonymous and were published upon the same day. Prof. 



