ABT. 10 TEOPICAL AMERICAN DIPTEEA — VAIT DUZEE 59 



posterior slope of thorax with thin white pollen; the usual velvety 

 black stripe above the root of the wing and the silvery spot at the 

 suture indistinct. Abdomen green, incisures and hair black, its 

 dorsum with considerable white pollen, spots of white pollen on the 

 sides of the segments, last segment wholly white pollinose. Hypo- 

 pygium moderately large, nearly sessile, black, dulled with white 

 pollen, lamellae elongate, rounded at tip, fringed with long black 

 hairs, nearly half as long as the hypopygium. 



All coxae, more than half of posterior surface of fore femora, nar- 

 row tips of posterior femora and all tibiae and tarsi black ; trochan- 

 ters, remainder of fore femora, middle and hind femora, lower sur- 

 face of fore tibiae, middle basitarsi except tip, and three or four 

 elongated spots on upper edge of each middle and hind tibia yellow ; 

 fore tarsi (fig. 71) with one claw enlarged to form a grasping organ; 

 joints of fore tarsi as 22-97-7-11; claw as 10; joints of middle tarsi 

 as 39-21-1&-15-12; those of posterior pair as 31-39-30-18-16. Ca- 

 lypters and halteres yellow, the former with black cilia. 



Wings grayish; third vein nearly straight; last section of fourth 

 vein arched from the cross vein to its tip, which is close to the tip of 

 third vein and in front of the apex of the wing. 



Described from two males and three females; one male, the type, 

 was taken at El Salto, Antigua, Guatemala, May 1, 1926; the rest at 

 San Cristobal, Alta Vera Paz, Guatemala, May 17, 1926; all were 

 collected by J. M. Aldrich. 



Type.— Male, Cat. No. 41070, U.S.N.M. 



This is very nearly like unguiculatus Aldrich and nigrifacies Van 

 Duzee ; from the latter it differs in having the face wholly pollinose, 

 from the former in having the face wholly without the median lon- 

 gitudinal depressed line, which is so conspicuous in unguicvZatus. 



PELASTONEURUS ACUTICAUDA, new species 



Male. — Length 2.3 mm. Face wide, silvery white, its sides parallel, 

 the suture near the middle, lower edge nearly straight; palpi and 

 proboscis black; front bluish, dull with gray pollen; antennae (fig. 

 72) yellow, first joint narrowly brown above, third joint mostly 

 brown, about as long as wide, rounded; lateral and inferior orbital 

 cilia white. 



Dorsum of thorax brown, with slight purple reflections and brown 

 pollen, quite shining; the velvety black stripe above the root of the 

 wing not very conspiciwus, the spot of white pollen at the suture 

 prominent; pleurae green with white pollen. Abdomen blackish 

 metallic with green and coppery reflections and spots of white pollen 

 on the sides of the segments. Hypopygium (fig. 73) black, its 



