AMERICAN DIFTERA. 251 



and spiny below, and bristly above ; hind tibiae glabrous, bent at 

 proximal fourth and from thence uniformly curved, sharp on inner 

 edge, rounded on the outer, the side faces flat. Middle tibiae on the 

 outer edge with three bristles; remaining hairs of the legs finer, 

 denser on the front and middle legs, though nowhere long. AVings 

 broad, rather pointed at the tip, anal angle prominent, rounded, 

 almost rectangular; veins strong; first posterior cell much nar- 

 rowed in the margin ; discal cell long and narrow ; outer section of 

 the fifth vein equal to the posterior cross vein ; outer section of the 

 sixth vein shorter than the anal cross-vein. 



liaclistoinyia insolita sp. nov. (Fig. 82). 

 Male. — Length 5.5 mm., length of wing 4.5 mm. Robust, piceous, with a 

 greenish tinge. Antennae piceous, exceedingly short, the arista a little shorter 

 than the eye height. Palpi and proboscis fuscous; proboscis one-fourth shorter 

 than the head. Eyes narrowly separated on the face. Thorax with golden pu. 

 bescence and brownish dust. Tegulse and halteres in fuscated, the former with 

 short yellow cilia. Abdomen dark olive green, pilose along the sides, twice the 

 length of the thorax; hypopygium large, reflexed, concolorous, except the 

 lighter metallic, fuscous distal portion, its sutures fringed with hair, the left side 

 with a larger, inverted, the right side with a smaller, bowl-shaped piece. Legs 

 short, stout, fuscous, shining, especially the hind legs, metallic by certain, reflec- 

 tions; coxae concolorous with the legs; anterior and middle femora, tibiae and 

 tarsi all of about the same length ; posterior coxae globose, swollen on the inner 

 side; posterior femora not surpassing the abdomen in length, enormously thick- 

 ened, sparsely hairy, on inner side bounding a narrow, smooth, shining space, 

 with two rows of tubercles, about eleven in the anterior row and seven in the 

 posterior, each tubercle provided with a stout spine; hind tibiae stout, one- 

 third less than the length of the femora, strongly incurved, without spines, but 

 with an external row of short hairs ; hind tarsi short, one-half the length of 

 the others, the first joint one-third longer than the remainder of the tarsus. 

 Wings strongly infuscated, of the same general color of the rest of the insect, no 

 darker stigma; rather pointed ; veins strong, thii'd and fourth longitudinal veins 

 convergent, ending symmetrically at the tip of the wing; discal cell narrow; 

 anal angle fully developed, anal vein strongest at the tip, though poorly marked. 



A single male specimen. Chapada, Brazil. A very curious insect. 



SYSTECHES Walker.* 

 Sraall, generally brownish species. Antennse shorter than the 

 head, apparently two-jointed, terminal joint rounded with a long 

 end-bristle. Proboscis short, palpi rather long. Eyes bare, con- 



* Almost the only note on the manner of feeding of American En)pididae is 

 to be found in the Proceedings of the Washington Entomological Society, 1891, 

 p. 146. There Mr. Schwarz describes the feeding habits of a species of Si/ueches : 



TRANS. AM. ENT. SOC, XXVIII. AUGUST, 1902 



