HYMENOPTERA. 185 



of the basal segment a tuft of white pubescence ; beneath, the 

 pollen-brush is yellowish white. 



Obs. The unique specimen described is probably worn by 

 exposure, the upper surface being nearly without pubescence, 

 and the wings are worn at the edges ; in general aspect it ap- 

 pears to belong to another genus, but is a true Megachile. 

 Hab. Para. (Coll. H. W. Bates, Esq.) 



123. MEGACHILE XANTHURA. 



Megachile xanthura, Spin. Mem. Accad. Torino, xiii. no. (>7. 

 Hab. Para. 



124. MEGACHILE SIMILLIMA, n. s. B.M. 



Female. Length 3^-4 lines. Black, on each side of the face 

 a line of snow-white pubescence, the cheeks and sides of the 

 thorax have a thin hoary pubescence ; a line of short white pu- 

 bescence in front of the tegulse, sometimes traversing their mar- 

 gin and passing along the base of the scutellum, usually more 

 or less interrupted ; the wings subhyaline, their nervures black ; 

 legs sometimes dark rufo-testaceous, covered with a short cine- 

 reous pubescence. Abdomen short and nearly triangular, the 

 apical margins having a narrow white marginal fascia ; beneath, 

 the pollen-brush is yellowish white. 



Obs. This species very closely resembles the European species 

 M. argent at a. 

 Hab. Para. (Coll. H. W. Bates, Esq.) 



125. MEGACHILE DENTICULATA. B.M. 



Male. Length 4 lines. Black, the face covered with white 

 pubescence, the clypeus naked, the cheeks have a long beard of 

 white pubescence ; the sides of the thorax are clothed and the 

 legs fringed with pubescence of the same colour ; the tarsi elon- 

 gate, the apical joints ferruginous, the calcaria testaceous ; the 

 wings fulvo-hyaline, the tegula? and nervures rufo-testaceous. 

 Abdomen Hat, the segments banded with white pubescence ; the 

 apical segment clothed with similar pubescence, its margin irre- 

 gularly denticulate ; beneath, the marginal bands are continued 

 on the second, third and fourth segments. 

 Hab. Brazil; Rio Tapajoz. (Coll. H. W. Bates, Esq.) 



126. MEGACHILE EXALTATA. B.M. 



Male. Length 3| lines. Black, head large, wider than the 

 thorax, the face densely covered with bright pale yellow pubes- 



