282 S. \V. WILLI8TON, M. D. 



75. Kristalis rufiTeiitris Macq. 



A uumbex' of specimens from Chapada agree very well with Mac- 

 quart's description, but positive determination is hazardous in the 

 absence of Columbian specimens. Some of the males have a quad- 

 rate black spot on the third abdominal segment. The female has 

 two spots of the second segment not attaining the hind margin, and 

 the two following segments each with an opaque posterior baud and 

 metallic in front, the third with an anterior opaque spot ; in some 

 there is red on the third segment. The facial stripe is rarely black. 



76. Eristalis scliistaceus n. sp. 



9 . — Leugth 9 mm. Face densely yellowish white pollinose, leaving the 

 median stripe and the cheeks shining black. Front on the sides yellowish pol- 

 linose, immediately above the antennae with a shining black spot, connected by 

 a linear stripe witli an opaque band above ; immediately below the autennje a 

 narrow yellow pollinose band. Antennse reddish browu. Mesonotum opaque 

 ashy gray, slightly yellowish, with a narrow band a little before the suture, and 

 another of equal width throughout behind, both interrupted by a line, opaque 

 black; the second baud is straight in the middle, making on each side an angle 

 to curve forward and outward to the root of the wing. Scutellum light waxy 

 yellow, its narrow base and the lateral margin opaque black. Pleurfe thickly 

 whitish pollinose, with white and yellowish pile. Abdomen : second segment 

 opaque black, with a large jiruinose metallescent .spot on each side, leaving a 

 posterior and a median stripe, and contiguous with the front border outwardly 

 only : third segment with an opaque blat^k posterior band and a median anterior 

 spot, a shining baud across the middle, and on the front, laterally, pruinose like 

 the spots of the second segment; fourth segment opaque black, with a shining 

 cross-band ; second, third and fourth segments each with a narrow yellow hind 

 margin. Legs black ; tibiae at the base narrowly yellowish. Wings nearly pure 

 hyaline. Hind femora thickened. 



One specimen, Chapada. 



77. Eristalis parvulus n. sp. 



9 . Length 7 mm. Face black, thickly ashy pollinose, leaving a rather broad 

 stripe and the cheeks shining black. Antennae reddish brown. Vertex opaque 

 black, a narrow ochraceous band in front of the ocelli and behind a broader 

 opaque black baud or spot, that is continued in a slender stripe to the shining 

 black above the base of the anteunse; the sides of the front below the opaque 

 spot yellowish pollinose. Mesonotum opaque yellowish ashy gray, leaving a me- 

 dian stripe gradually attenuated to a point anteriorly, a small spot in front of the 

 inner end of the suture, and a large triangular spot behind the suture, extending 

 to the .scutellum posteriorly and outwardly along the suture to the margin, all 

 opaque black. Scutellum at the sides metallic black, on its base above opaque 

 black, leaving a rounded yellow spot above on the apical part. Pleurae black, 

 moderately shining. Abdomen opaque black ; second segment with a triangle 

 on each side, and the three following segments each with an entire band, metallic 



