2o6 MEMOIRS ON THE COLEOPTERA 



known, except as a mere suggestion in Leptura matthewsi. Our 

 species are heterogeneous and form four subgeneric groups as fol- 

 lows: 



Third antennal joint very much longer than the fourth; emargination of 

 the eyes extremely feeble, broadly sinuate 2 



Third and fourth joints equal, both much shorter than in the preceding 

 section; emargination deep and subangulate 4 



2 Eyes rather coarsely faceted, larger and more prominent; fossa of 

 the fourth palpal joint short, not attaining base or apex; pubescence 

 even. Atlantic regions Group I 



Eyes always very finely faceted and relatively small in size 3 



3 Middle coxae rather widely separated by the broadly tumid meso- 

 sternum; elytra substriate, rugose, the pronotum nude and almost 

 sculptureless; last palpal joint shorter, obtriangular, with the fossa 

 entire, very deep; pubescence even. Atlantic regions Group II 



Middle coxae very moderately separated as usual; elytra never substriate, 

 the prothorax always densely punctate and pubescent, with much 

 less irregular surface and less acutely angulate lateral tubercles; 

 palpal fossa deep, nearly attaining the apex but not the base; elytral 

 pubescence uneven in lay, partially transverse or oblique. Atlantic 

 and Pacific regions Group III 



4 Middle coxae very moderately separated; antennal swellings more 

 pronounced and basal; narrowing of the head more abrupt than 

 in any of the preceding; sides of the prothorax medially not so 

 prominent, arcuate between the constrictions; pubescence even. 

 Atlantic regions and Europe Group IV 



The influence of geographic habitat is very pronounced in the 

 evolution of these groups. 



Group I. 



Subgenus Toxotopsis nov. 



The single known species is the Leptura cinnamoptera of Randall 

 (cBSCuli Hald.); it is well known and apparently very constant in 

 form, showing that it is geologically old ; it needs no special descrip- 

 tion at this time. 



Group II. 



Subgenus Eutoxotus nov. 



The type of this subgenus is the large and stout Toxotus schaumi 

 of LeConte. The body is generally wholly black, the femora alone 

 red, but black at base and apex. Mr. Leng has described a sub- 

 species under the name croceus (Ent. Amer., 1890, p. 68), which is 



