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 siurface 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. 67. 

 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 tegulae, 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. argentata. 

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



125. Megachile denticulata. B.M. 

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



pubescence, the clyjieus 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-hvaline, the tegulse and nervures rufo-testaceous. 

 Abdomen flat, 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 3i lines. — Black, head large, wider than the 

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



