BRAZILIAN MUTILLA. 15 



fiddle-shaped, broad in front, constricted laterally at base of metathorax. the ante- 

 rior angles acutely carinate ; two short teeth on each side near base of meso- 

 thorax ; the stigniatic tubercles at base of metathorax prominent and white; 

 metathorax broad, depressed, lateral margin with five long acute teeth ; first 

 segment of abdomen dilated posteriorly, the apical margin slightly constricted ; 

 second segment densely sculptured, and on each side at base above a promi- 

 nent longitudinal dentated crest, and a short longitudinal carina on each ex- 

 treme side; apical segment convex, smooth and shining. 



Honey-yellow, with pale pubescence more or less mixed with blackish ; head 

 more or less varied with yellowish ; thorax ferruginous, posterior margin of pro- 

 thorax, a spot on its middle and a spot on base of metathorax, sometimes continued 

 narrowly to apex, and sometimes extended forward on mesothorax, black or fus- 

 cous; legs entirely honey-yellow, with pale pubescence; calcaria white; second 

 segment of abdomen more or less yellowish, the crests, and sometimes a stain on 

 sides and lateral apical margin of the segment, black or fuscous. 



Santarem. Easily recognized by the pale color, and the two 

 prominent black dentated crests on base of second segment of 

 abdomen. 



This is doubtless denticulata Smith, although the punctuation is 

 fine, and the denticulated tubercles or crests on second abdominal 

 segment are prominently black ; the teeth at sides of metathorax 

 are long, slender and acute. 



2. M. cornigera 9- — Length 6.5 mm. — Small, rather slender; head not 

 broader than thorax, subquadrate, depressed, rounded posteriorly and prolonged 

 behind eyes, which are small, rounded, not very convex, polished; thorax ovate, 

 rounded above, slightly narrowe.d in front, and rapidly so behind, not con- 

 stricted, the anterior angles tuberculate; metathorax subcompressed, sides not 

 dentate; abdomen ovate, first segment broad posteriorly, sessile with base of sec- 

 ond, which is very densely punctured, and on each side at base a group of five or 

 six prominent tubercles. 



Black ; antennse, thorax, most of legs and first segment of abdomen, ferrugin- 

 ous; tibiae, apical segment of abdomen above and venter fuscous; a short stripe 

 at base of second segment above between the groups of tubercles, a narrow band 

 on apical margin, and a spot on disk of segments 3-5, of silvery white pubes-- 

 cense; calcaria pale; apex of abdomen with yellowish pubescence, the ventral 

 segments fringed at apex with white pubescence. 



Chapada. One specimen (May). Easily recognized by the tu- 

 berculate base of second abdominal segment. 



3. ]II. deeiissata 9. — Length 10 mm. — Head subquadrate, broader than 

 thorax, slightly narrowed and extending a considerable distance behind the 

 eyes, which are rounded, very convex and polished; cheeks carinate; thorax 

 ovate, not constricted laterally, anterior angles carinate; metath(nax short, grad- 

 ually narrowed posteriorly, the lateral margin with a row of short acute teeth ; 

 legs slender ; abdomen ovate, first segment nodose, second segment densely punc- 



TKANS. AM. ENT. SOC, XXVIII. JANUARY, 1902. 



