hymenoptera. 377 



39. Centris nigrescens. 



Centris nigrescens, St. Farg. Hym. ii. 166. 32 S . 

 Hab. Ca3'enne. 



40. Centris obsoleta. B.M. 



Centris obsoleta, St. Farg. Hym. ii. 153. 7 ? {and type sp. in Coll. 

 JVestw.). 



The male has the thorax irregularly garnished with lines of 

 pale yellow pubescence. 



Hab. Cayenne ; Brazil (Rio Tapajos and the Amazons). 



41. Centris pyropyga. 



Hemisia pyropyga. Spin. Ann. Soc. Ent. Fr. x. 148. 99 $ (1841). 

 Hab. Cayenne. 



42. Centris scapulata. 



Centris scapulata, St. Farg. Hym. ii. 159. 18 $ . 



Hab. Cayenne ; Columbia. (Coll. W. W. Saunders, Esq.) 



43. Centris pcecila. 



Centris poecila, St. Farg. Hym. ii. 154, 10 $ {type sp. in Coll. 

 Westw.). 



Hab. Ilavannah. 



44. Centris fasciata. B.M. 



Female. Length 7 Imes. — Head and thorax black ; the cly- 

 peus has a somewhat curved transverse fascia, from the middle 

 of which a line terminating in a point passes upwards to the 

 base ; the face on each side, the labrum and mancUbles j^ellow, 

 the latter black at their tips ; the scape yellow in front, the fla- 

 gellum, except the two basal joints, testaceous beneath. Thorax 

 clothed above with fulvo-ochraceous pubescence, paler on the 

 metathorax and beneath ; legs rufo-testaceous ; tibiaj and tarsi 

 clothed above with fulvo-ochraceous pubescence, that on the 

 tarsi brightest ; wings hyaline and ii'idescent ; the basal segment 

 of the abdomen of a metallic green, the following segments 

 yellow, their apical margins having a fascia of a rufo-testaceous 

 colour, having a metallic green tinge ; beneath reddish-yellow , 

 the third and fourth segments having a transverse fuscous stain. 



Male. — Rather smaller, but closely resembling the female, 

 differing only in having the yellow of a brighter colour on the 



