282 THE CANADIAN ENTOMOLOGIST. 



Exojna, n. gen. 

 Body small, oval, very convex, the elytral striae so deeply impressed 

 as to form coarse sulci ; head deflexed, deeply inserted, subquadrate, the 

 arcuate frontal margin reflexed, the clypeus short, broadly arcuate ; labrum 

 large, transverse, sinuate, vertically inflexed under the clypeus; maxillary 

 palpi slender, the last joint oval, acuminate ; eyes basal, flattened, trans- 

 versely oval, with convex separated facets ; the antennae are i r-jointed, 

 inserted in small ante-ocular excavations, slender but short, the basal 

 joint thicker, oval, the last three larger, gradually increasing and forming 

 a loose club; prosternum broadly lobed anteriorly, flattened and produced 

 between the coxae, its sinuato-truncate apex received within a mesosternal 

 pit between the middle coxte ; metasternum ample, the episterna narrow 

 and completely fused ; abdomen with five free segments, much above the 

 plane of the metasternum ; epipleurae broad, parallel and horizontal to the 

 end of the metasternum, being there abruptly broken, ascending and 

 thence much narrowed posteriorly, disappearing before the apex; the 

 posterior wall of the metasternum and epipleura forms a shelter for the 

 hind thighs ; legs short, the two anterior free though retractile ; tarsi well 

 developed, 5 -jointed, coarsely hairy, the first and fifth joints of the 

 posterior elongate, the three intermediate shorter. 



The peculiar epipleural structure and the sulcate elytra constitute of 

 this genus such a marked exception that it is impossible to associate it 

 with any thus far known ; its divergencies are apparently tribal or sub- 

 tribal in nature. The type is the following : 



E. pletiralis, n. sp. — Deep black, shining, the upper surface with 

 short, erect, curved setae, very easily removed and forming a single series 

 on each of the convex elytral intervals, more persistent on the head and 

 pronotum, which are frequently covered with concealing foreign matter ; 

 head finely, sparsely punctulate, the erect setae very small and inconspicu- 

 ous ; prothorax transverse, at base as wide as the elytra, narrowed 

 anteriorly, the surface with very minute and remote aSperulate punctula- 

 tion bearing the stronger curved setje ; elytra barely as long as wide, 

 inflated basally and widest at about basal third, rapidly narrowed thence 

 to the narrowly-rounded apex. Length, 1.5-1.6 mm.; width, 0.9-1.0 

 mm. British Columbia (Metlakatla). 



This genus will be considered again in a general revision of the 

 American Byrrhidae which the author has in contemplation, and he takes 

 this occasion to say that material of any kind in this family, from any part 

 of the continent, would be most welcome, 



