AUT. 19 AMERICAN MUSCOID FLIES ALDRICH 19 



The front is yellow poUinose above, silvery below, which color ex- 

 tends down around the eye and across the face. The parafrontals 

 are niiicli narrower than in sericea except below. Palpi and pro- 

 boscis small and yellow. Thorax with cinereous pollen abo\e; hu- 

 meri yellow in <rround color: pleurae with silvery pollen extending 

 down the middle part. Thoracic chaetotaxy as in sericea, but the 

 acrostichals are very small and the scutellum has a small pair of dis- 

 cal bristles: the abdomen shining yellow to about the middle of the 

 third segment, the remainder shining black except below: a very dis- 

 tinct silvery pollinose crossband on the base of the third and fourth 

 segments; first segment without median marginals; second with one 

 pair and one lateral : third and fourth each with marginal row of 

 six: on the venter there is a marginal pair of bristles close together on 

 the second and third segments, arising from the tergites, which in 

 the specimen overlap considerably. 



"Wing almost as in sericea, the infuscation a little more diffused; 

 third vein with distinct hairs extending far beyond the cross vein ; first 

 vein hairy from base to tip, no costal spine. Coxae and femora yellow 

 (the front femora missing) ; middle tibia slightly infuscated, with 

 two good-sized bristles on outer front side, two smaller on outer hind 

 side, and one small on flexor surface; tarsi black; hind tibia more 

 densely infuscated, with almost villous hairs on the flexor surface, 

 four bristles of varying size on outer hind side ; four on outer front 

 side, only the last of which is of noticeable size. 



Length, 5.5 mm. 



Not represented in the United States National Museum. 



124. CALLESTHES DILECTA Wiedemann 



MuHca dilectd Wiedemann, Auss. Zweifl., vol. 2, 1830, p. 419. 

 ? Zosteromi/ia dilecta Brauer and Bekgenstamm, Zweifl. Kais. Mus., pt. 5, 

 1891, p. 406. 



One male indicated as type, '' Brasilien, Coll. AVinthem.'' Agrees 

 with original description, but is in rather poor condition. All of the 

 legs are gone but one (middle). The head is pressed in from below, 

 which must have occurred when the specimen was fresli a century ago 

 or more; this prevents a complete description of the head structures. 

 The thorax has been damaged by the pin. Undoubtedly the type. 

 I refer the species provisionally to my recently described genus Calles- 

 thes^ of which the type is Callesthes Mstno Aldrich, from Ecuador, 

 described in the same place. Callesthes dilecta differs in having much 

 narrower parafrontals, the wing distinctly brown, bend of fourth vein 

 much more abrupt. The two species agree in the striking transverse 

 band just before the suture, extending down to the sternopleurae, and 



"Pioc. U. S. Nat. Mus., vol. 74, art. 1, \y. 11. 



