344 Trans. Acad. Sci. of St. Louis. 



sides not parallel but evidently converging from the rounded basal 

 angles to the apex, barely three-fourths wider than the head, similarly 

 wholly unimpressed ; elytra nearly similar but more transverse, evidently 

 shorter and narrower than the prothorax; abdomen at base as wide as 

 the elytra, thence strongly and arcuately narrowed to the apex, which 

 is relatively much narrower than in omata. Length 1.7 mm.; width 0.8 

 mm. Arizona (Phoenix) arizonlca n. sp. 



No didtinct sexual modifications are apparent, the sixth 

 tergite being broadly bilobed at tip in each of the single 

 types at hand. 



BOLITOCHARINI. 



Silusa Er. 



Besides the two species described below, this genus will 

 include the American species califormca Bern., and vesperia 

 Csy., these having the peculiar oral structures of Silusa; but 

 the form that I have identified as gracilis Sachse, does not 

 seem to be a true Silusa, having more the facies of Xep- 

 tusat and Silusa nanula Csy., belongs evidently to a differ- 

 ent genus : — 



Form parallel, not very stout, convex, shining, the Integuments wholly de- 

 void of minute sculpture, blackisb, the elytra, abdominal apex and 

 apices of all the segments paler, castaneous; legs pale, tbe antennae 

 fuscous, pale at tip and toward base; pubescence not dense, moderate 

 in length; punctures fine, not close, impressed and simple, those of the 

 elytra larger, close-set and asperate, sparse and flue throughout on the 

 abdomen; head wider than long, tbe eyes moderate ; antennae extending 

 to basal third of the elytra, stout and gradually incrassate distally, the 

 elongate second and third joints equal, the subapical moderately trans- 

 verse, the eleventh pointed and as long as the two preceding; prothorax 

 two-fifths wider than long and fully one- half wider than the head, tbe 

 sides broadly arcuate, more converging toward apex, the basal angles 

 obtuse but not rounded, the surface with a feeble transverse impression 

 before the scutellum ; elytra only just visibly wider but two-flfths longer 

 than the prothorax, strongly and broadly impressed behind the scutel- 

 lum, the impression paralleling tbe sutural margin posteriorly; abdo- 

 men narrower than the elytra, parallel, the first three tergites strongly 

 and broadly impressed at base, the fourth more narrowly and feebly; 

 hind tarsi short, the first four joints short and subequal. Length 3.8 

 mm. ; width 0.88 mm. New York (Catskill Mts.) , — H. H. Smith. 



ralens n. sp. 



Form much stouter, moderately convex, shining, pale flavo -testaceous, the 

 head and a large ante-apical abdominal cloud blackish, the elytra verj 

 faintly shaded with piceous toward the external apical angles; punc- 



