100 PROCEEDINGS OF THE NATIONAL MUSEUM vol.87 



35. Gular sutures always united, at least basally 36 



Gular sutures never united in any part 41 



36. Head coarsely umbilicately punctured or with coarse and deep 



elongate punctures; without dense ground sculpture through- 

 out - - 37 



Head not or indistinctly umbilicately punctate; with dense 



ground sculpture ^ 40 



37. Punctures of head very dense; labrum with denticles in pairs 



only 38 



Punctures of head not very dense; labrum with median tooth 39 



38. Head emarginate at base; labrum with median teeth separated 



by twice their average width, notch rounded; pronotum 



punctured very differently from head Pachystilicua 



Head not emarginate at base; labrum with median teeth sepa- 

 rated by less than twice their average width, notch not 

 rounded; pronotum punctured similarly to head Stilicus 



39. Labrum with median tooth only Acrostilicus 



Labrum with additional teeth... — Stiliderus 



40. Head obtriangular; labrum without prominent teeth; head, 



pronotum, and elytra with short, stiff, erect bristles Megastilicus 



Head suborbicular; labrum with prominent teeth; with only 



normal pubescence Stilicolina 



41. Head with dense, coarse, umbilicate punctures Medome 



Head very finely punctate (or sparsely obsoletely umbilicately punctate) 42 



42. Labrum not dentate, feebly emarginate; vertex sometimes 



carinate in males Monista 



Labrum generally quadridentate; vertex not carinate in males Scopaeus 



A. Head, pronotum, and elytra almost impunctate, with sparse long upright 



hairs subgenus Scopaeodera 



Head, pronotum, and elytra finely or moderately punctate or sculpttired .B 



B. Head truncate or emarginate behind subgenus Scopaens 



Head strongly rounded behind O 



0. Inner labral teeth modified on inner edge, generally denticulate subgenus Scopaeopsia 



Inner labral teeth without additional iimer denticle or other modification... subgenus Scopaeoma 



43. Presternum connate vdth edge of hypomera 44 



Prosternum not connate with edges of hypomera 51 



44. Antennae anteriorly flexile, basal segment very much elon- 



gate _ Cephalochetua 



Antennae posteriorly flexile, basal segment not very elongate 45 



45. Prothorax very elongate; head grooved behind eyes; third seg- 



ment of maxillary palpus globose Sphaeronum 



Prothorax generally not very elongate; head not separately 

 grooved behind eyes; third segment of maxillary palpus large 

 but not subspherical 46 



46. Head, pronotum, and elytra with strong tuberculi and dense 



ground sculpture ...Myrmecosaurus 



Head and pronotum with feeble umbiUcate punctures, without 



ground sculpture 47 



47. Labrum denticulate 48 



Labrum not denticulate _ _ Sclerochiton 



48. Labrum quadridentate 49 



Labrum bidentate 50 



49. Integuments not very densely punctate, with prominent shining 



^^^e^vals Nazerii 



