264 NORTH AMERICAN TRYPETINA. 



Shining black; head yellowish; occiput black, with a pale yel- 

 low border; front broad, more bright yellow ; only the spot upon 

 which the ocelli are placed and the small, very narrow stripes, 

 which run down from the vertex upon the front, are of a blackish 

 color; the usual frontal bristles are black. Antennae of a vivid 

 ochre-yellow ; their last joint is elongated-oval, obtuse at the end ; 

 arista blackish, with a hardly perceptible pubescence. Oral 

 opening rather large, somewhat longer than broad; its anterior 

 edge drawn up, but not projecting in the profile. Proboscis and 

 palpi short, brown, the latter more clay-yellow towards the tip. 

 The thoracic dorsum shows two longitudinal stripes, rather dis- 

 tant from each other, somewhat abbreviated posteriorly and 

 covered with a thin, white pollen ; upon the anterior part of the 

 thoracic dorsum a similar pollen covers not only the interval 

 between the stripes, but also extends beyond them. The whole 

 of this pollen, however, is but little conspicuous and seems to be 

 easily rubbed off. The humeral angle and a stripe running from 

 it towards the root of the wings, are white. The flat scutellum, 

 with the exception of its lateral border, has the same color. 

 Metathorax without any pollen, altogether shining deep black. 

 The usual bristles of the thorax and the four bristles of the scu- 

 tellum are deep black. The other hairs on the thoracic dorsum 

 are very short and delicate. Abdomen shining black ; its first 

 two segments are more opaque, being clothed with a brownish- 

 black pollen. The first three segments, upon their posterior mar- 

 gin, have a crossband of a whitish pollen. The very short and 

 soft hairs upon the abdomen are black ; the paler crossbands 

 upon the posterior border of the first three segments show some 

 whitish hairs ; the bristles upon the sides of the intermedi- 

 ate segments and upon the rather large last segment are 

 black. Ovipositor shorter than the last abdominal segment, 

 broad at the basis, much narrower at the end, shining black 

 and with a black pubescence. Second coxal joint pale clay -yel- 

 lowish. Femora black, only the extreme tip yellowish-brown ; 

 tibia? and tarsi pale clay-yellowish ; the former somewhat more 

 brownish at the basis ; the bristles upon the upper side of the 

 hind tibia? are remarkably short. Wings pure hyaline, almost 

 whitish hyaline, with four entire black crossbands, the first of 

 which of a medium breadth, the three others very broad The 

 first band is somewhat oblique and begins on the humeral cross- 



