ART. 15 NOTES ON ACALYPTEATE FLIES MALLOCH 29 



Genus DI A ST AT A Meigen 



KEY TO THE SPECIES 



1. Wings fuscous, with numerous hyaline spots, or hyaline with numerous small 



dark spots; cheeks less than one-sixth of the eye height (Subgenus Spilo- 



chroa Williston) 2. 



Wings hyaline, sometimes partly clouded with brown, never with clear-cut 

 pale or dark spots ; cheek much over one-sixth of the eye height ( Subgenus 

 Disastata Meigen). 



2. Subcostal cell of wing with a small dark spot in center, or largely brownish_3. 

 Subcostal cell of wing entirely whitish hyaline 5. 



3. Mesonotum grey dusted, and with three brown vittae, the laterals along the 



lines of dorsocentrals, all three imited posteriorly ; thorax and abdomen 

 dark brown below and on sides, the dark color extending narrowly along 

 the dorsal edges of abdominal tergites, and each tergite with a central 

 brown mark on a grey dusted ground ; subcostal cell of wing almost entirely 



fuscous, darkest in center dimidiata (Hendel). 



Mesonotum grey dusted, but without well-defined vittae ; thorax and abdomen 

 not colored as above; subcostal cell whitish hyaline, with a small dark 

 central spot 4. 



4. Abdomen dull chocolate brown, with numerous irregular grey dusted spots on 



tergites ; discal cell of wing dark brown, with two or three hyaline spots 

 in the apical half which are sometimes partly fused, and at least one 



smaller spot near the base ornata (Johnson). 



Abdomen glossy, varying in tone from black to yellowish with blackish apices 

 to the tergites ; discal cell of wing dark brown, with a hyaline spot beyond 

 its middle polita, new species. 



5. Scutellum dark brown, with a pale grey dusted spot at apex and one on each 



side at base; wings black-brown, the marginal cell with two large hyaline 

 spots beyond apex of first vein dividing the cell into three almost equal 

 parts, and sometimes a faint additional pale spot at its apex. 



peruviana, new species. 

 Scutellum pale grey dusted, entirely without brown markings 6. 



6. Wings black-brown, with small clear-cut hyaline spots, three of them in the 



marginal cell, the second posterior cell with four hj^aine spots ; prescutellar 



acrostichal bristles lacking albibasis, new species. 



Wings hyaline, with the dark markings much reduced and not sharply mar- 

 gined, the marginal cell with three diffuse dark marks, and the second pos- 

 terior cell with three, one in center, one at apex, and one at base along the 

 inner cross vein ; prescutellar acrostichal bristles present but weak. 



punctipennis (Melander). 



DIASTATA (SPILOCHROA) DEWIDIATA (Hendel) 



Trlxoscelis dimidiata Hendel, Deutsch. Ent. Zeitschr., 1913, p. 617. 



I have not seen this species, but the description includes details on 

 the structure of the head and thorax, and the photographic figure of 

 the wing is so clear that there can be no question as to the generic 

 location of the species. The color markings of the thorax and abdo- 

 men readily distinguish it from any other species known to me and 

 also from Diastata chilensis Schiner,* the latter not being included in 



* Novara Reise, Diptera, p. 235, 1868. 



