. APPENDIX C. — INSECTS. 367 



HYUEMOPTERA. 



Among the most interesting entomological discoveries in the 

 imperfectly explored parts of the United States territory, that of 

 the three new species of the genus Lahidus must be included. This 

 is a tropical form, and almost exclusively confined to Brazil, the 

 most northern species hitherto described being from the West In- 

 dian Island of Saint Vincent. The three species were discovered 

 at Fort Gates by Lieutenant Haldeman. 



Labidus saji, Hald. 



Pl. IX. Fig. 1-3. 



Luteous, head brown above, and having (with the mandibles and 

 basal articulation of the antennae) piliferous punctures ; stemmata 

 large, and the posterior ones twice as far from each other as from 

 the eyes ; face excavated below the antennae, with the lateral cari- 

 nas sharp or angular, and the medial line impressed ; mandibles 

 large, tapering slowly, and curved from the base. Thorax convex 

 and shining, with numerous piliferous punctures ; dorsal line nar- 

 row and distinctly impressed from the most prominent part to the 

 anterior margin. Peduncle triangular, excised posteriorly with 

 well-developed exterior angles. Abdomen indistinctly pubescent, 

 with piliferous punctures posteriorly. Feet slender, simple, and 

 uniformly coloured ; base of the anterior tarsi excavated beneath for 

 the tibial spur ; ungues bifid ; posterior feet extending beyond the 

 abdomen ; tibial spurs small. Wings with the stigmata long and 

 narrow, posterior half indistinctly sanguineous, the nervures of 

 the colour of the body, the membrane a pale tint of the same 

 colour, and translucent. Length eight and a-half, wing seven and 

 a-half, posterior tarsus two and a-half lines. 



Labidus harrisii, Hald. 



Pl. IX. Fig. 4-6. 



Polished and pubescent, above black, abdomen rufous. Head 

 black, pubescent; stemmata large, posterior ones three times 

 farther from each other than from the eyes ; antennae pale fulvous, 

 base pilose ; mouth rufous ; mandibles pilose, robust, curved at the 

 base only, the inner edge rectilinear, and the apex acute but not 



