BYRRHID^E 5 



Mesosternum as in the two preceding tribes; mandibles concealed in 

 repose by the prosternal lobe; elytra generally finely punctate and 

 chagrined, the punctures generally fine and very close, the surface 

 always striate, the striae generally shallow and fine though abrupt, 

 not impressed, regular in position though sometimes contorted 

 slightly BYRRHINI 



Mesosternum much narrower, wholly occupied by the deep transverse 

 pit receiving the obtuse tip of the prosternal process; mandibles 

 apparently not concealed in repose; elytra deeply sulcate; size 

 minute EXOMINI 



The first three of these tribes are widely distributed throughout 

 the subarctic regions of the world, while the fourth is represented 

 by a single anomalous species from the coast regions of British 



Columbia. 



Tribe PEDILOPHORINI. 



In general form and sculpture, as well as in many structural 

 features, this tribe plainly connects the more typical Byrrhids 

 with the preceding very isolated Nosodendron. The several genera 

 are definable and easily distinguishable by peculiarities of abdominal 

 and tibial structure, as well as type of sculpture of the elytra and 

 abdomen. The general structure is otherwise rather uniform 

 throughout; and the antennae are moderately short, gradually 

 broader and compressed apically through the last six joints, the 

 first stout, the third more or less elongate, slender and cylindric. 

 The seven genera in my collection may be defined as follows: 



Tibiae broad, very obtusely angulate externally or obliquely truncate 

 externally at apex; crural depressions of the abdomen very shallow 

 and gradual in formation, extending through the second segment, 

 the sutures all fine, the first obsolete, the posterior feebly arcuate; 

 frontal edge just behind the labrum sinuous, the sinus filled with 

 pale coriaceous membrane. [Type P. anratus Duftsch.]. Palae- 

 arctic *Pedilophorus 



Tibiae less broad to slender, straight or feebly and evenly arcuate in 

 outline externally throughout; frontal edge behind the labrum 

 transverse, straight and unmodified; crural depressions of the ab- 

 domen never extending behind the first segment; all the sutures 

 distinct 2 



2 Crural depressions of the abdomen very shallow and gradual in for- 

 mation, undefined, the tarsi always free in repose 3 



Crural depressions deep and abruptly formed, well defined to shelter 

 the femora and tibiae, the tarsi free; punctures of the elytra not 

 evenly disposed as in the genera preceding but denser or sparser at 

 various parts of the surface 8 



3 Legs stout, the tarsi short: vestiture of the upper surface recumbent, 



