378 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.52. 



corner of fourth posterior cell are three Httle cells, representing an 

 abnormality only. 



Oligocene: Gurnet Bay (Brodie). British Museum, I. 8666. This 

 minute fossil fails to show the base of the wing, but most of the vena- 

 tion is very well preserved. I can only interpret it as a relative of 

 Mythicomyia, which has the same type of second vein, only more ex- 

 treme. In Mytliicomyia the third vein may be a httle deflected at 

 the anterior cross-vein, or it may be straight. Tlie anal cell is usually 

 closed, but Cresson shows that it may be narrowly open. The shape of 

 the wing in Mythicomyia is very different from that in the fossil. 

 Cresson and others place Mythicomyia in the Empididae, and the fossil 

 must be referred to the same family, 



RHAMPHOMYIA HYPOLITHA. new species (Empididae). 



Plate 31, fig. 8. 



Male. — Length, 6 mm.; wings, 4 mm.; head, thorax, and legs 

 black; abdomen slender, dark brown; wings dusky, but not fuhginous; 

 proboscis directed downward, somewhat longer than head; antennae 

 about 608 p. long, the end formed as in R. sepulta. Praefurca very 

 short, strongly curved; anterior cross-vein before middle of disca 

 cell; anal cell as usual in the genus. The following measurements 

 are in microns: Praefurca, not allowing for curve, about 176; sub- 

 marginal cell at apex, not allowing for curve of margin, 880; first 

 posterior cell on wing margin, 400; second posterior on margin, 560; 

 basal corner of discal cell basad of vertical level of end of praefurca, 

 96; first basal cell on submarginal, 240; first basal on discal, 320; 

 first posterior on discal, 560; total length of discal, 880. 



Florissant, in the Miocene shales. Easily known from R. sepulta 

 Cockerell, the other Florissant species, by the wing measurements. 



Type.— C&t. No. 62538, U.S.N.M. 



URORTALIS, new genus (Ortalididae). 



A genus of the subfamily Richardiinae, with extremely long, taper- 

 ing ovipositor; wings without any conspicuous markings. Costa 

 minutely bristly; auxiliary vein approaching costa very obliquely; 

 first vein without bristles; second vein straight at end (not curved 

 upward as in Richardia); first posterior cell not at all contracted 

 apically; superior apical corner of discal cell forming an obtuse angle. 

 Hind femora stout; whether toothed or not can not be determined. 

 The venation, except for the shape of the first posterior cell, is 

 nearly as in Epiplatea; as in that genus the basal costal region is 

 large, not narrowed as in Stenomacra. The region of the anal cell 

 is extremely obscure, but it seems to be short and truncate or sub- 

 truncate. This is not a very satisfactory genus, the characters of tha 



