80 Mr. F. Smith on some new Oenera and Species 



Family Pompilidae, Leach. 

 Genus Planiceps, Latr. 



1. Planiceps concolor. 



P. nigro-violacea, sericea et iridescens ; alis anticis nigro-purpxu'eis mi- 

 cantibus, alis posticia pallidioribus viridi-tinctis. 



Female. Length 5 lines. Deep blue, with brilliant reflexions in dif- 

 ferent positions; the mandibles obscurely ferruginous; the antennas 

 black. Thorax : the wings beautifully iridescent, the anterior pair dark 

 brown, the posterior pale fusco-hyaline ; the anterior tarsi rufo-testa- 

 ceous, the intermediate tibiae and tarsi slightly spinose. The abdomen 

 of a smooth shining iridescent blue. 



Hab. Mexico. 



All the species of the genus Planiceps are insects of great rarity : 

 four have been previously recorded ; the two described in the present 

 paper are, perhaps, the most beautiful that have been discovered. 



2. Planiceps notabilis. 



P. nigerrima, sericea ; abdomine supra plagis quinque albido-luteis notato, 

 2-2"l ; alis nigi-is, \'ix iridescentibus. 



Female. Length 7\ lines. Black, subopake, and covered with a fine 

 silky silvery pile ; that on the vertex and disk of the thorax has a purple 

 iridescence ; the mandibles obscurely ferruginous at their apex ; the 

 scape of the antennfe compressed ; the posterior ocelli situated on the 

 posterior margin of the vertex. Thorax : the wings very dark brown 

 and slightly iridescent ; the intermediate and posterior tibite and tarsi 

 slightly spinose. Abdomen : a large subovate yellomsh-white spot on 

 each side of the second and third segments, and a single one at the base 

 of the apical segment. 



Hah. Mexico, 



Family Nyssonidse, Leach. 



Genus Pison, Spin. 



1. Pison maculipennis. 



P. niger, subtiliter punctatus, sericeo-pubescens ; capite antice aureo- 

 villoso; thorace, pedibus abdominisque segmento primo et secundo 

 ferrugineis ; alis hyalinis, maculis fiiscis. 



Fetnale. Length 4^ lines. Head black, the face densely covered with 

 golden pubescence ; the scape, three basal j oints of the flagellum, the 

 clj'peus and mandibles ferruginous. The thorax, legs and abdomen 

 with a pale silky pubescent pile ; the thorax ferruginous as well as the 

 legs ; the post-scutellum and sides of the metathorax black ; the apical 

 joints of the tarsi slightly fuscous; the wings hyaline, tlie externo- 

 medial and the marginal cells occupied by a dark-fuscous cloud, the 



