WILLIAM G. DIETZ 133 



A very distinct species. Closely allied to P. xanthostigma, 

 with which it agrees in the antennal structure, the shining occiput 

 and coloration of wings, and from which it is readily distinguished 

 in its dark testaceous or ferruginous color, the abdominal seg- 

 ments conspicuously — especially in the female — banded with 

 black and the very differently constructed hypopygium. 



All the specimens were taken in a rather circumscribed marshy 

 locality, where rarely more than one or two specimens were 

 taken in a season. 



Pachyrhina obliterata spec. n. (PL V, fig. 15; pi. VII, fig. 31.) 



Yellow. Flagellar joints of antennae bicolorous, blackish at base. Occiput 

 shining. Thoracic stripes ferruginous, the transverse suture black externally. 

 Abdomen with dorsal stripe and lateral rows of spots, dark fuscous. 



Male. Length, 14 mm.; wing, 12.5 mm. 



Head concolorous. Proboscis very short, sides fuscous; frontal prolongation 

 with two ferruginous lines, beset with dark hairs, more dense on the nasus. 

 Mouthparts brown. Palpi yellowish-brown, the last joint shorter than the 

 three preceding joints. Face pale yellow and like the front, opaque. Anten- 

 nae of moderate length and thickness, the three basal joints dark yellow, the 

 following joints dusky yellow and, with the exception of the apical joints, dis- 

 tinctly emarginate beneath, above the basal enlargement, the latter blackish, 

 hairs of the verticel blackish and rather long; pubescence fine, whitish. Occi- 

 put shining, extending triangularly upon the vertex. 



Thorax shining, sulphur yellow. Pronotal scutum and scutellum tinted 

 with fuscous, the former with a pale line each side. Dorsal stripes ferruginous, 

 the middle stripe narrowed posteriorly, lateral stripes curved outward ante- 

 riorly ; the interspaces between the middle and lateral stripes, margined black 

 on their anterior margins. Scutum with a broad stripe each side, which leaves 

 but a narrow margin of the ground color externally and a nearly parallel, me- 

 dian stripe. Scutellum and broad median stripe of postnotum ferruginous. 

 Transverse suture heavily black in middle section, less so on its exterior ends, 

 again very conspicuously so in the pleuro-dorsal suture before the alar inser- 

 tion. Pleura concolorous, sternopleura inferiorly, and a few small, incon- 

 spicuous spots, ocherous. Halteres dark yellow, club brown, apex paler. 

 Legs slender, dark yellowish covered with a dense, grayish pubescence, femora 

 and tibiae lightly infuscate towards the apex, outer joints of tarsi fuscous, 

 metatarsi longer than the tibiae. Wings with a grayish tint, dispersedly 

 pubescent; costal veins, vein R and the veins beyond the cord with the excep- 

 tion of those limiting cell 1st M 2 setulose; costal cells and margin of vein Cu, 

 pale yellow; stigma yellowish with a fuscous tint, apical part lightly infuscate. 



Abdomen yellow with light fuscous touch, a dark brown dorsal stripe, paler 

 posteriorly and more or less interrupted, extends from the base to the sixth 

 tergite, the seventh tergite apically and the eighth nearly entirely, blackish; 

 a lateral row of large, elongate black spots, alternating with fine black strigae; 



TRANS. AM. ENT. SOC, XLIV. 



