34 E. T. CRKSSON. 



serrate ; flauks of thorax with a broad, deep, polished excavation on posterior 

 lialf ; ahdonien ovate, first segment very broad, sessile with base of second and 

 conforming in outline therewith; pygidium smooth and shining; first segment 

 beneath unarmed. 



Black, clothed above with short, decumbent, black pubescence; cheeks, face 

 and scape of antennje with pale glittering pubescence; an oblique stripe on each 

 side of vertex and on lateral margin of thorax above as far as verge of truncation 

 on metathorax, of silvery pubescence; metathorax behind with long pale ])uhes- 

 cence; legs and venter piceous or fuscous, shining, clothed with pale pubescence; 

 calcaria whitish ; abdomen at base and sides with scattered pale pubescence, sec- 

 ond segment with two rather large, longitudinally ovate, opaque yellow or red- 

 dish spots; apical middle of segments 3-5 with a spot of silvery pubescence. 



Chapada. Easily recognized by tlie overhanging projection on 



the front. 



4.3. !tl. »ra.xsi 9 ■ — Length 8-14 mm. — Head transversely quadrate, slightly 

 broader than thorax, posterior angles rounded, carinate ; eyes convex, smooth 

 and polished ; thorax short, fiddle-shaped, dee])ly constricted on each side behind 

 the middle; lateral margin of mesothorax with two or three short, obtuse teeth 

 before the constriction ; metathorax abruptly declivous posteriorly, the lateral 

 margin serrate, flanks broadly and rather deeply excavated about the middle, 

 smooth and shining; abdomen ovate, first segment broadly dilated posteriorly, 

 sessile with base of second segment and conforming in outline therewith ; apical 

 segment above very closely and finely punctured. 



Velvety black above; clypeus, cheeks — extending up on each side of vertex 

 obliquely behind the eyes, scape, a stripe on each side of thorax above extending 

 from prothorax almost to apex of metathorax, sides of pro- and mesothorax, a 

 si)ot above the four posterior coxse, tufts on each extreme lateral apical margin of 

 abdonnnal segments 2-5, and a square spot on apical middle of segments 3-5, of 

 pale golden or silvery pubescence ; sides of metathorax with long white hair; 

 legs clothed with whitish pubescence, calcaria jiale, tarsi often more or less rufo- 

 te.staceous; second abdominal segment above with two rounded, subopaque yel- 

 low or orange-yellow spots, one on each side midway between base and apex; 

 venter sometimes reddish, clothed with whitish pubescence, the segments fringed 

 at apex with rather long whitish hair. 



Chapada, Corumba. At first sight this h>oks like projectifrons, 

 but besides the plain front, the head is not emargiuate behind, the 

 thorax is longer, and the pale spots on second abdominal segment 

 are rounded, not oval. 



44. W. tlirnalis 9- — Length 10 mm — Densely and strongly punctured; 

 head transversely subquadrate, slightly broader than thorax, posterior margin 

 straight, lateral angles rounded and carinate; cheeks unarmed, but sharply cari- 

 nate beneath ; eyes small, rounded, convex, smooth and polished ; thorax short, 

 fiddle-shaped, a little longer than broad, broader anteriorly, rather deeply con- 

 stricted about the lateral middle, with two or. three small teeth on lateral margin 

 in front of the constriction ; metathorax abruptly truncate behind, the lateral 



