NORTH AMERICAN HYMENOPTERA. 249 



dorsal segment with pale sparse pubescence. Wings subhyaline, nervures and 

 tegulse testaceous, the recurrent nervures very near each other on the cubital 

 nervure. Length 9 — 13 mm. 



Texas, Arkansas (Say), Mexico. 



20. Tacliytes obsciirus Cress. 



9 . — Anterior margin of clypeus rounded, not emargiuate, with two obtuse, 

 extreme lateral teeth ; mandibles large, broad and with the notch on outer mar- 

 gin narrow ; vertex with fine, distinct punctures; medial impressed line distinct, 

 depression behind ocelli strong and contains an arch-like impressed line; an- 

 tennje much longer than in sericatns, third joint shorter than the fourth, but 

 when seen in certain position appears to be about equal, joints 10 and 11 over 

 three times longer than their width ; space between eyes at top greater than the 

 length of the second and third antennal joints; region enclosed by the ocelli 

 strongly impressed medially. Thorax, with exception of metathorax, punctured 

 like the vertex ; metalhorax. except sides, subopaque, almost smooth, above with 

 a distinct fovea at apex, the posterior face with a medial furrow similar to that 

 of the male of sericatus ; tibiae armed with short, stout, black thorns, those on 

 the tarsi longest; first joint of hind tarsi about as long as the two following 

 united, possibly a little shorter. Abdomen above and segments 1 and 2 beneath, 

 finely and closely punctured ; basal portion of ventral segments 3 — 6 smooth and 

 shining, the apical portion with large, sparse punctures, black; mandibles rufo- 

 piceous ; face and clypeus clothed with dense silvery pubescence; cheeks, collar 

 above, apical margins of segments 1 — 3 laterally and the legs with silvery pile. 

 Head and thorax clothed with long, pale pubescence. Wings subhyaline; tegulse 

 and nervures dull testaceous; pygidium silvery at base, the remainder bronzy. 

 Length 13—14 mm. 



"5^ . — Of the same form as sericatus, but smaller and scarcely silvery ; anteunse 

 rather long, stouter than in sericatus, foui'th joint one-third longer than the pre- 

 ceding one and slightly longer than the fifth joint, joints 5 — 7 about equal in 

 length: region enclosed by the ocelli distinctly impressed medially, but not so 

 strongly as in sericatus; vertex and thorax finely and distinctly punctured; 

 metathorax above appearing impunetate, the fovea at apex elongate and shallow, 

 posterior face granulated, the medial sulcus strongest basally. Abdomen finely 

 and closely punctured. Wings hyaline, nervures testaceous; tibise and tarsi 

 densely clothed with silvery sericeous pile. Length 7 — 9 mm. 



District of Columbia, Georgia, Texas, Mexico. 



21. Tachyfes parvus n. sp. 



%. — Resembles o6sc«rHs; front strongly depressed before the anterior ocellus 

 so that it presents two rather strong protuberances; region encrlosed by the ocelli 

 also very strongly furrowed ; space between eyes at top about equal to the length 

 of joints 2 — 4 of antenna; united; fourth joint of antennae longer than third, 

 the fourth is shorter than the fifth, joints 5 and 6 equal ; dorsulum with 

 scarcely a depression anteriorly ; metanotum appearing smooth, not furrowed, 

 the fovea at apex tolerably distinct; tibia; and tarsi distinctly spinose, the 

 spines anil the tibial spurs whitish. Abdomen above and beneath finely and 

 closely punctured ; emargination of eighth ventral segment deep, wider than in 

 obscnrus, black ; front, clypeus and sides of thorax with silvery pile, the legs and 



TRANS. AM. ENT. SOC. XIX. (32) SEPTEMBER, 1892. 



