282 HYMENOPTERA. 



quence of the errors discovered in those of St. Fargeau in the 

 ' Histoire naturelle des Insectes '; after a careful microscopic 

 examination of several individuals of this genus, only riidiment- 

 ary palpi or a small tubercle has been found in the maxillae ; 

 St. Fargeau gives six joints in his characters. The genera Me- 

 soplia, Hopliphora and Mesonychium of St. Fargeau are stated 

 by that author to agree with the genus Mesocheira in the cha- 

 racter of the oral organs ; on a careful examination of those 

 parts they are foimd to differ very widely, and the difference in 

 the number of spines which arm the large calcaria of the inter- 

 mediate tibiae cannot be considered as affording anything beyond 

 specific distinctions. 



1. Mesocheira bicolor. B.M. 



Melecta bicolor, Fair. Syst. Piez. p. 386. 3. 



Mesocheira bicolor, St.Farg. 4" Serv. Ency. Meth. x. 106. 



Crocisa bicolor, Jurine, Hym. p. 241. 



In this species the scutellum is produced over the base of the 

 abdomen and deeply notclied. 



Hab. Brazil ; Cayenne. 



2. Mesocheira sericeus. 



Mesocheira sericeus, Guer. Icon. Reg. Anim. p. 456. 

 Hab. Rio Janeiro. 



3. Mesocheira asteria. 



Female. Length 5 lines. — Head and thorax black, the face 

 covered with silvery-white pubescence, a line of similar pubes- 

 cence passes along the margin of the vertex and down the outer 

 margin of the eyes ; the flagellum iiifo-piceous beneath ; the base 

 of the scape ferruginous in front. Thorax, tlie tubercles and 

 tegulae in front rufo-piceous ; the scutellum bituberculate ; a 

 line on the collar continued round the tubercles, and the margins 

 of the scutellum bordered with white pubescence ; at the sides of 

 the metathorax a tuft of white pubescence ; the wings hyaline at 

 their base, and having a fuscous cloud at their apical margins, 

 the nervures black ; the spurs at the apex of the intermediate 

 tibiae elongate, filiform, slightly bent, and notched at the apex, 

 one side of the notch produced into a sharp spine, the other side 

 bidenticulate ; the spines on the posterior tibia? finely serrated 

 within. Abdomen conical, of a beautiful bright green, having a 

 silken texture ; the sides adorned with silvery-white markings ; 

 beneath testaceous, having spots of purple colouring, the sides of 



