20 Trans. Acad. Sci. of St. Louis. 



3 — Neck more or less broad; fourth palpal joint distinct, more or less 

 conical Cryptobia 



Neck extremely slender as in Scopaeus; fourth palpal joint indistinct, ap- 

 parently obtuse and more or less pubescent *Sphaerouia 



4 Ligula bilobed at tip; sculpture and vestiture never very dense; labrum 



never strongly dentate at the middle 5 



Ligula densely fimbriate at tip ; labrum dentate only at the middle ; sculpture 

 and vestiture very dense, the surface devoid of lustre 8 



5 _ Fourth joint of the maxillary palpi compressed and lineate at apex and 

 clothed with fine pubescence 6 



Fourth palpal joint conical, sometimes aciculate, always nude 7 



(5 — Neck very broad; body feebly convex; hind tarsi filiform... *Dolicaoiie8 



Neck narrow; body strongly convex; tarsi with the fourth joint lobed be- 

 neath Paederi 



7 — Anterior tarsi always strongly dilated in both sexes, the posterior fili- 



form and simple; body more or less parallel as In Dolicaones and mod- 

 erately convex as a rule Lathrobia 



8 — Body more or less parallel and feebly convex; anterior tarsi vari- 



able Lithochares 



9 — Ligula loosely fimbriate at tip ; neck never very slender Medones 



Ligula tricuspid at tip; neck variable but never very broad Scopaei 



10 — Prosternum remaining far below — viewed from below — the level of 



the edges of the hypomera, with a widely open space between the two 

 surfaces; tarsi filiform, the fourth joint simple; antennae as in Paederi; 

 neck very slender Stilici 



Prosternum approaching very close to the edge of the hypomera in a verti- 

 cal sense, the opening between them narrow but evident; tarsi short 

 and stout, the fourth joint bilobed; antennae straight, not flexile at 

 the first joint, the apex of the latter not sinuate behind; neck very 

 slender Stilicopses 



Prosternum touching or connate with the edges of the hypomera, the coxal 

 cavities entirely chitinous 11 



11 — Fourth tarsal joint bilobed; antennae straight, not flexile at the flrst 



joint, the apex of which is not sinuate behind; mentura simple; max- 

 illary palpi slender, the third joint elongate and fusiform, the fourth 

 small, obtuse and inconspicuous; neck moderately narrow; integuments 



moderately dense ; species small in size Snnii 



Fourth tarsal joint simple; antennae flexile, the apex of the flrst joint 

 sinuate posteriorly; mentum usually modified at the sides, sometimes 

 spinose; third joint of the maxillary palpi more or less securiform or 

 otherwise abnormal, the fourth very minute and indistinct; neck usually 

 very slender; integuments thicker and much denser; species generally 

 very small in size Ecliiasteres 



In the following pages 89 genera are defined in the tables 

 of o-enera, of which 64 occur within the limits of the United 

 States of America and 25 are exclusively foreign; these 

 latter are distinguished in each case by a prefixed asterisk. 



