148 PROCEEDINGS OF THE NATIONAL MUSEUM vol. lu 



flection; trochanters black; only foretibiae and midtibiae yellow; last 

 three joints anterior tarsi and all of other pair dark; all posterior tibiae 

 black, not violaceous; wings hyaline hardly dusky at tip, violaceous 

 in reflected light; abdomen black in certain light, brilliant blue and violet 

 in other light, pruinose; head more aciculate than punctured; antennae 

 yellow beneath, brown above; upper interocular distance (17) slightly 

 less than lower; ratio of third and fourth antennal joints is 11:11; length 



8.0 mm. Mexico 22. roseiis, new species 



4G. Rody black, antennae black; wings fuscous 47 



At least thorax strongly some shade of green or blue 49 



47. Pygidium mat, not shining; body dull black, opaque; eyes distinctly con- 



verging above; lateral ocelli 1.7 as far from eyes as from each other; clypeus, 

 cheeks, and head not with silvery pubescence; length 8.5 mm. Panama. 



obsciinis (Banks) 

 Pygidium shining, impunctate 48 



48. Eyes distinctly converging below; clypeus and cheeks densely covered with 



silvery pubescence and long black hairs; lateral ocelli twice as far from 

 eyes as from each other; thorax covered with long pale fulvous hair which is 

 especially long on sternum; first recurrent vein received beyond middle of 

 second cubital cell; length 9.0 mm. Mexico .... perditus Cameron 

 Eyes not converging below, upper and lower interocular distances about 

 equal; clypeus and cheeks with little silvery hair and with short white hairs; 

 lateral ocelli not quite twice as far from eyes as from each other; thorax 

 with only a very little short white hair on either dorsal or ventral surface; 

 first recurrent vein received by the second cubital cell in the middle; 

 length 6.7 mm. Bermuda 56. bermudensis, new species 



49. Head and abdomen black, thorax bluish green with very strong purple re- 



flection over almost whole surface; head and thorax with medium length 

 light hair; antennae black, slender; coxae shining black, with faint bluish 

 reflection; legs beyond coxae black, with faint bluish reflection, but apices 

 of tarsi more brownish; abdomen black shining, pruinose; wings fuscous; 

 ratio of upper interocular distance to lower is 16:17; lateral ocelli 2.5 as far 

 from eyes as each other; ratio of length of third and fourth antennal joints 

 is 11:8, hence third antennal joint five-eights of vertex width; length 6.0 mm. 



Costa Rica 33. fuscus, new species 



Head and abdomen not black 50 



50. Body entirely bright blue, tinged with green on thorax; clypeus and face with 



strong silvery pubescence, and rest of head and thorax with rather strong 

 sericeous pile; antennae entirely black; thorax with beautiful violet re- 

 flection in certain light; tegula black; propodeum rugose toward tip, es- 

 pecially on sides; wings hyaline, with bright slightly yellowish reflection, 

 veins brown; legs blue with purplish reflection; size 8.5 mm. Cuba. 



bellus (Cresson) 

 Body not entirely bright blue 51 



51. Wings noticeably fuscous; larger length about 8.0 mm; thorax bright green 



without purple reflection or if thorax not bright green the apical half of 



thorax with strong purple reflection 52 



Wings clear hyaline, or if slightly fuscous abdomen black or if bluish wings 

 with coppery iridescence; size smaller, length about 6.0 mm 53 



52. Thorax shining bright green, abdomen very dark with bluish reflection, 



shining; head not as bright colored as thorax; clypeus broadly rounded in 

 front; upper and lower interocular distance equal (19); ratio of lengths of 

 third and fourth antennal joints is 11:10; lateral ocelli 1.5 as far from eyes 



