Dec, I9I3-] MeLANDER: SYNOPSIS OF DiPTERA. 287 



Ovipositor not of remarkable structure; anal cell at least present 25. 



25. Acrostichal setulse and hairs of front absent or greatly reduced ; bristles 



and hairs black; discal cell usually fused with the second basal; 

 cross-veins rather close together ; usually no oral vibrissa ; one to 

 three f ronto-orbitals ; upper occiput rather concave. (Europe, Asia, 



North America.) Tethina Haliday. 



Acrostichal and frontal hairs present; hairs and bristles often yellow or 

 white ; discal cell separated from the second basal ; oral vibrissa more 

 or less differentiated 26. 



26. Cheeks with a marginal row of hairs; face nearly vertical or projecting; 



cinereous species ; ultimate section of fifth vein usually shorter than 

 the penultimate section of the fourth ; three or four fronto-orbitals, 



outwardly bent. (Europe, North America.) Rhicnoessa Loew. 



Cheeks hairy; face receding; ground-color yellow; ultimate section of fifth 

 vein equal to or longer than the penultimate section of the fourth 



vein 27. 



2j. Two or three reclinate fronto-orbitals ; center of face small and deeply 

 sunken ; upper occiput flattened. (Europe, Africa, North America.) 



Aphaniosoma Becker. 



Three fronto-orbitals, the front pair convergent; center of face not deeply 



impressed ; occiput rather convex. (Europe, Asia, North America.) 



Chiromyia Desvoidy. 



SINOPHTHALMUS Coquillett. 



This genus is aberrant in the Geomyzinse. It differs from all the 

 other genera of this group before me in having the calypteres entirely 

 without cilia; the auxiliary vein very short, entirely vanishing half- 

 way to the costa, the costal break immediately before the end of the 

 first vein ; the costa showing a weak spot beyond the humeral cross- 

 vein corresponding to the first costal break of other subfamilies; the 

 basal cross-vein of the discal cell is interrupted; the lateral prolonga- 

 tions of the center of the face occupy a large part of the cheeks; the 

 mesopleurse entirely bare ; and the face with central protuberance. 



The genus is certainly quite similar to Drosophila rcplcta Wollas- 

 ton, differing indeed only in the family characteristics, such as the 

 separate basal cell and pubescent arista. The two are such replicas 

 of each other, so similar in size, color, vestiture, chsetotaxy, and pro- 

 portions of parts, that it is hard to believe that their similarity is the 

 result of convergence and that they should be assigned to separate 

 subfamilies. 



But a single described species. 



