NO. 2061. HYMENOPTERA FROM GUATEMALA— ROHWER. 521 



the scutellum, narrow lateral spots on the first to fourth tergites, the 

 apices of the four anterior femora beneath, the four anterior tibiae 

 except a Hne above, basal spot on the posterior tibiae externally, 

 yellow; tegula piceous; sqamae, spines, and calcaria paUid ; flagellum 

 beneath, the three apical joints above and the anterior tarsi fuscous; 

 wings hyaline, faintly dusky, strongly iridescent; venation dark 

 brown; apical abdominal segment bright red. 



Male. — Length, 3.5 mm. A single specimen which for the time 

 being may be considered as the male of the species, differs from the 

 female as described above in the following characters: The fovea of 

 the posterior face of the propodeum V-shaped, the apex of the V 

 being almost at the ventral margin of the posterior aspect of the 

 propodeum; pronotum, tubercules and scutellum black; the four 

 anterior tibiae and tarsi, the base of the posterior tibiae and the pos- 

 terior tarsi yellow (the tarsi are rather paler). The apical dorsal 

 segment of the abdomen angularly notched, the lobes triangular in 

 outhne. 



The spots on the second, third, and fourth tergites may be wanting 

 or incomplete. 



Quirigua, Guatemala. Described from three females and one 

 male collected by W. P. Cockerell, February, 1912, bearing the fol- 

 lowing note, ''nesting in sand." 



Type.— C&t. No. 15085, U.S.N.M. 



RHOPALUM OPACUM, new species. 



Differs from Rhopalum spinigerus Cameron by the absence of the 

 spines on the anterior femora and other characters, nor will it agree 

 with the description of Rhopalum angulicolle Cameron, being easily 

 distinguished from this species by the pale four anterior femora. 



Male. — Length, 4 mm. Anterior margin of the clypeus regularly 

 rounded, without teeth; distance between the eyes at the clypeus sub- 

 equal with the length of the second and third antennal joints; head 

 finely granular ; an impressed hne from the anterior ocellus to between 

 the bases of the antennae; ocelli in an equilateral triangle; post- 

 ocellar line distinctly shorter than the ocellocular Hne; third antennal 

 joint much shorter than the fourth; pronotum long, rounded ante- 

 riorly, neither dentate nor carinate; thorax opaque, finely granular; 

 the suture between the metanotum and the propodeum strongly 

 foveolate; propodeum finely granular; the four anterior legs normal, 

 the posterior tibiae strongly curved beyond the basal fourth, posterior 

 basitarsis curved basally, subequal in length with the two following 

 joints; petiole not strongly nodose, not as long as the two following 

 segments combined; first recurrent vein shghtly beyond the middle 

 of the first cubital cell; first transverse cubitus straight, not obHque. 

 Black; mandibles, palpi, scape, flagellum beneath, tubercules, the 

 apical lateral margin of the third tergite, the anterior legs, inter- 



