of Exotic Hymenoptera 149 



the superior wings with one marginal cell, truncate at its apex ; with three 

 submarginal cells, the first as long as the two following, which are both 

 slightly narrowed towards the marginal cell ; the second submarginal cell 

 receiving the first recurrent nervure at its base, nearly uniting with the 

 first transverso-medial nervure, the third submarginal receiving the second 

 transverso-medial nervure at its apex, uniting with the third transverso- 

 medial nervure. Abdomen oblong-ovate and subdepressed. 



1. Apista opalina. 



A. capite thorace pedibusque nigris ; clypei marginibus mandibulisque 

 ferrugineis ; flagello fulvo, tegulis, alarum venis, tarsorunique articulia 

 apicalibus rufo-testaceis ; abdomine pallide femigineo subopalino. 



Female. Lengtb 6 lines. Head, thorax, and legs black ; the 

 clypeus anteriorly and the mandibles ferruginous; the flagellum, ex- 

 cepting the two basal joints, fulvous, slightly fuscous above; a little 

 pale downy pubescence in front of the anterior stemma and along the 

 inner margin of the eyes. The thorax above has a short, dense, sooty- 

 black pubescence, blending into white at the sides and beneath; a 

 narrow line of white pubescence passes over the tegulae and base of the 

 scutellum ; the floccus on the posterior femora beneath is dense, white, 

 and of a woolly texture ; the legs beneath and the apical j oints of the 

 tarsi rufo-piceous ; the scoppe on the posterior tibiae short, dense, and 

 black; the wings hyaline and iridescent, the nervures ferruginous. 

 Abdomen oblong-ovate, pale ferruginous, with a beautiful opaline 

 iridescence, and longer than the head and thorax ; the apical margins 

 of the first and three following segments with a narrow fascia of white 

 pubescence ; the two apical segments with ferruginous hairs intermixed 

 with fuscous ones at the sides ; the apical segment has a small black 

 naked triangular space in the middle, carinated at the sides. 



Hab. Brazil. Mr. H. W. Bates. In my own Collection. 



This insect has a strong resemblance in form to Apis mellifica ; it 

 is altogether a most singular bee ; its situation in arrangement must, 

 I think, be between the genera Macropis and Andrena. 



Genus Megacxlissa, Smith. 



1. Megacilissa notabilis. 



M. capite thoraceque nigris, thorace abdominisque basi pube fuliginoso- 

 nigra dense vestitis ; abdomine rubro ; alis subhyalinis. 



Female. Length 8 lines. Head and thorax black ; the cheeks and 

 clypeus densely covered with short white downy pubescence ; eyes very 

 large and approximate at their vertex ; the mandibles short and slender, 

 bidentate at their apex ; the flagellum piceous beneath. Thorax 

 wider than the head, densely clothed with short downy sooty-black 

 pubescence, having a velvety appearance ; the legs obscure ferruginous, 



VOL. I. 31 



