Scarabaeidae of Nebraska 109 



Pronotum normally punctured, fixed spur of hind tibiae scarce- 

 ly half as long as the movable spur praetermissa 



21. Fifth abdominal sternite with a more or less well developed 

 transverse ridge, the crest of which is usually somewhat dark- 

 ened and roughened 22 



Fifth abdominal sternite without a transverse ridge, the longi- 

 tudinal impression of the under surface of the abdomen ending 

 on this sclerite in a well defined, slightly roughened depression, 

 rear edge of the sternite distinctly emarginate or notched at 

 the middle inversa 



22. Transverse ridge of fifth sternite strongly and evenly ai'ched in 

 the middle, and with the ends of the ridge attaining or over- 

 hanging the rear margin of the segment fervida 



Transverse ridge of fifth sternite much less strongly bent, the 

 ends not attaining or overhanging the margin of the segment 23 



23. Transverse ridge of the fifth sternite bisinuate behind, evenly 

 rounded in front, and strongly roughened on the prominent, 

 flattened middle portion draki 



Transverse ridge of fifth sternite more or less arched instead 



of bisinuate behind 24 



24. Terminal portion of genital armature rounded with the tips 



of the two sides turned inwardly and nearly or quite touching.. ../nsca 



Terminal portion of genital armature triangular with the tips 



of the two sides distinctly separated, not turned inwardly anxia 



25. Last abdominal sternite with a median triangular impression, 

 the posterior margin of the impressed area distinctly bi- 

 lobed , congruu 



Last abdominal sternite not so modified, the posterior margin 

 not bilobed at the middle glabricula 



26. Pubic process absent, superior genital plates nearly as broad 

 as the interior plates, united and keeled at the middle, emarg- 

 inate at the end futilis 



Pubic process present 27 



27. Pubic process distinctly divided, bilobed or split 29 



Pubic process single 28 



215 



