APPENDIX.
323
2. B. populator. Black; abdomen red; wings dark fuliginous.
Inhabits United States.
% 9 Metathorax rough, with confluent punctures; abdomen entirely reddish-fulvous; oviduct black, longer than the abdomen.
Length of the body two-fifths of an inch.
A very common insect in many parts of the United States. The head and stethidium are sometimes dark pi-ceous with the anterior portion of the thorax black. It resembles B. initiator, Fabr.
3.  B. ligator. Black, abdomen and feet rufous, antennas with a white annulus.
Inhabits Pennsylvania.
9 Vertex and occiput impunctured ; annulus of the antennas placed beyond the middle; palpi piceous; stethidium with confluent punctures ; thorax with two dilated, abbreviated, longitudinal, dull rufous lines; scutel with a dilated, longitudinal, dull rufous line; wings hyaline, ner-vures fuscous ; metathorax dull rufous ; feet rufous, tarsi blackish at tip; posterior thighs with a strong tooth beneath near the tip ; posterior tibise fuscous; posterior tarsi whitish; tergum punctured, glabrous at tip; oviduct blackish.
Length seven-twentieths of an inch.
4. B. stigmator. Dark yellowish-rufous; metathorax and first segment of the tergum black.
Inhabits North-west Territory.
Jintennse as long as the body, dusky towards the tip ; vertex between the stemmata black; occiput all round the neck, blackish; metathorax above and on the sides black; pleura with a blackish, dilated, longitudinal line; pectus with a blackish, dilated line before the anterior feet, reach-