424 Mr. T. D. A. Cockercll — Descriptions and 



large, with a few small irregular basal plicae, and a median 

 raised line continuous to hind margin ; posterior truncation 

 of metathorax not clearly defined as usual, its upper lateral 

 corners not defined at all, but its upper middle separated 

 by a short ridge from the basal area, while an oblique 

 ciliated ridge limits it on each side ; abdomen impunctate, 

 microscopically transversely lineolate, first segment nar- 

 rowed. Wings clear, very faintly dusky apieally ; recurrent 

 nervures ending a little before the transverso-cubitals j 

 second submarginal cell nearly square, its inner and outer 

 sides parallel ; bases of tibiae, and anterior tibiae in front, 

 cream-colour ; tarsi pale ferruginous. 



Oaxaca, Mexico, April 30 {L. 0. Howard). U.S. National 

 Museum. 



Looks like some small Pemphredonid wasp, but is a true 

 bee, with many plumose hairs on body. It is more or less 

 related to VachaFs P. recisa, P. puerula, P. fissa, &c, but 

 much smaller and very distinct. 



Prosopis subgrisea, sp. u. 



5 . — Length about 7 mm., anterior wing 5*3. 

 Black, with yellowish-white or brownish-white markings ; 

 mandibles and labrum black ; clypeus long, black, the lower 

 margin suffusedly reddish, but with a cream-coloured stripe 

 running down its middle (not quite reaching upper end), 

 not quite so broad as the area on either side ; supraclypeal 

 mark small, roundish ; lateral face-marks linear, extending 

 along orbital margins nearly halfway up front ; scape 

 and base of flagellum ferruginous, rest of flagellum black 

 above and faintly reddish below ; front appearing granular ; 

 upper part of prothorax with linear light margin, and greater 

 part of tubercles light ; a light band covering anterior half 

 of scutellum, a band on postscutellum, and axillae light ; 

 mesothorax dull, coarsely punctured ; area of metathorax 

 with coarse rugae ; posterior truncation and sides of meta- 

 thorax densely covered with pale grey tomentum ; pleura 

 sparsely punctured ; tegulae with a light spot. Wings 

 brownish hyaline, with the costal field, including marginal 

 cell and beyond, fuliginous ; hind tibise with rather more 

 than basal half white. Abdomen dullish, the punctures 

 excessively minute and close ; first and second segments 

 with yellowish-white marginal hair-bands, third to fifth with 

 hind margins obscurely pallid ; apex with dark fuscous 

 hair. 



