Sept., I9I3-] Melander: Synopsis of Diptera. 229 



Hendel's figures show the proboscis to be like that of Rhicnoessa and 

 the wing like that of Desmometopa. It is included twice in the key 

 to the genera in order to avoid confusion. 



Rhicnoessa and Tethina have been variously shifted. The front 

 sometimes possesses hairs similar to the cruciate bristles of the 

 Milichiinae, in which group they have usually been tabulated, but the 

 structure of the face and cheeks is very much like that found in the 

 Geomyzinse. With the latter group they find their best location, as is 

 shown by the single break in the costa, the pollinose body and espe- 

 cially the pollinose front, the more or less excavated occiput, and 

 the strong bristles, particularly of the pleurae, such as the paired pro- 

 thoracic and the row along the posterior side of the mesopleuree. 

 However, the auxiliary vein terminates in the first vein leaving the 

 break in the costa close to the end of the first vein, and not some dis- 

 tance before, as is otherwise the case in the Geomyzina^ before me, 

 while the chitinized and lengthened proboscis and the sometimes 

 prominent visbrissal angles show great similarity to Milichiine char- 

 acteristics. Professor Aldrich first suggested to me the identity of 

 Peloniyia Williston with Tethina. 



Table of Subfamilies. 



Auxiliary vein separated from the first vein, sometimes touching it before the 

 end and then again separating so as to end much before the termina- 

 tion of the first vein; postverticals convergent or wanting; costa 

 complete, at most slightly weakened just before the end of the aux- 

 iliary vein ; densely gray-pruinose species, abdomen usually pictured 

 with brown or black spots; oral vibrissae wanting or not differentiated ; 

 frontal suture transverse, not highly arched : interfrontalia differ- 

 entiated only by a difference in color or sheen of the pollen, without 

 cruciate inner frontal bristles, the ocellar triangle pollinose; occiput 

 flattened ; oral margin not deeply excised in front, center of the face 

 broad, relatively flat and not impressed beneath the plane of the 

 orbits, no vibrissal angle ; genje and buccse of cheeks not differen- 

 tiated ; proboscis short, not bent back at the end ; prothoracic bristles 

 wanting ; one posterior sternopleural ; mesopleurje usually bare, rarely 

 with sparse setae; front femora with a series of uniform bristles on 

 the outer flexor edge ; no preapical bristles on tibiae, middle tibiae with 

 apical spur ; calypter large, ciliate ; anal angle of wing well developed, 

 anal vein entirely rudimentary, basal cells complete. .Ochthiphilin^. 



Auxiliary vein fused with the first vein for much of its length, or entirely 

 rudimentary; costa broken at least before the end of the first vein; 



