216 E. T. CRESSON. 



velvety-black, basal segment with a long thin white pubescence, npex of seg- 

 ments 1 — 4 with a band of dense silvery-sericeous pile, segments 5 and 6 en- 

 tirely black; apical segment bright silvery. Length .55— .05 inch. 



Ten specimens. (Belfrage; Boll.) This may be the $ of dis- 

 tinetus, Smith. 



Tachytes validus, n. sp. 



9 .—Robust, black : face and clypeus with dense pale golden pubescence ; ver- 

 tex as in elongatus ; back of head with short pale golden pile, long and silvery 

 on cheeks beneath; middle of mandibles reddish; antennre as in preceding 

 species; thorax clothed with a dense dull golden pubescence, more dense on 

 sides of mesothorax and longer and paler on metathorax; prothorax with 

 bright silvery pile in certain lights; posterior face of metathorax with a deep 

 central channel, not reaching apex; scutellum with shallow depression on 

 disk; tegulse dull fulvous; wings pale yellowish-hyaline, paler at apex; legs 

 with golden pubescence, black, tibiae and tarsi fulvous, sometimes the femora 

 are more or less tinged with fulvous; abdomen black, basal segment with a 

 pale silky pubescence; apex of segments 1 — 4 with a silvery sericeous band, 

 apical segment bright golden. Length .70 inch. 



^ . — Very much like elongatus, differing by the metathorax being densely 

 clothed with a pale golden pubescence and by the wings not being margined 

 at apex with dusky; the form is also much more robust in every way, the ab- 

 domen being wider and somewhat flattened above, while that of elongatus is 

 narrow and convex. Length .65 inch. 



Three specimens. (Belfrage.) More robust than distinctus, Smith, 

 from which it may be distinguished by the pubescence of the thorax 

 being much more dense, by the wings not being margined at apex 

 with dusky, and by the abdomen having four silvery sericeous bands 

 instead of three. 



Three % specimens (which I had labelled breviventris) differs only 

 by the abdomen being short and subconvex and the femora fulvous at 

 tips. Length .55 inch. 



Tachytes sericatus, n. sp. 



9 . — Black ; face, clypeus, back of head, posterior margin of prothorax, 

 mesothorax, especially at sides and behind, postscutellum, metathorax and 

 pleura, clothed with a very short, fine silvery sericeous pile, vcr}' brilliant in 

 certain lights; clypeus broadly and deeply margined at apex; vertex sculp- 

 tured as in clongatus ; metathorax with a small fovea on apex above and a 

 deep channel on middle of posterior face, not reaching apex ; teguhe dull lute- 

 ous ; wings hyaline, tinged with yellowish toward base; legs black, with a 

 silvery pile, especially dense on tibite; abdomen strongly silvery sericeous and 

 when viewed obliquely from behind segments 1 — 4 have each a bright silvery 

 band at apex; apical segment dull silvery. Length .60 inch. 



%. — More slender than 9 > tne body less brilliantly sericeous, the wings 

 clear hyaline and the apical segment of abdomen bright silvery. Length .50 

 inch. 



Two % 9 specimens. (Belfrage.) 



