74 PROCEEDINGS OF THE- ACADEMY OF [Part I 



and Cui. Venation: Rs short, straight or feebly convex as in the 

 genus, cell 1st Ri consequently subtriangular as in C. paradoxa and 

 allies; Ro+z a little more than one-half Rs; basal deflection of Ri 

 perpendicular to R0+3, in alignment with r; basal deflection of 

 J?4+6 punctiform, almost in alignment with Rs; r-m long, about two- 

 thirds of Rs; cell Mz very deep, vein Mz originating basad of the 

 deflection of Cui, in all other species of the genus, vein Mz arises 

 distad of the deflection of Cui and cell Mz is consequently petiolate; 

 in the present species, cell Mz is entirely sessile; there thus aq)pears 

 to be a long m-cu crossvein preserved that is about half as long as 

 the deflection of Cui. Abdomen lacking. 



Habitat. — Peru. 



Holotype, Sex?, Yurimaguas, April 10, 1920 (H. S. Parish). 



Although the type specimen of this interesting new species of 

 Cryptolahis is badly eaten by Psocids, it is described in order to 

 present a new venational peculiarity in the tribe, the apparent re- 

 tention of the 7n-cu crossvein. The discovery of this fly lends sup- 

 port to Tillyard's theory of a four-branched media in the gener- 

 alized Diptera. By adopting this theory in the present instance, 

 the apparent 7n-cu crossvein becomes the basal section of M4 and 

 this would seem to be a far more logical interpretation than to 

 consider the element as being m-cu, since this is lacking in almost 

 every known Limnobiine crane-fly. 



Geniis GNOPHOMYIA Osten Sacken. 

 1859. Gnophornyia Osten Sacken, Proc. Acad. Nat. Sci. Phila., p. 223. 



Species of Gnophornyia are rather numerous in the Amazonian 

 Region. Additional species will very probably be discovered, es- 

 pecially in Peruvian territory. 



Gnophornyia rubicundula sp. n. 



General coloration black, the mesonotum and dorsal thoracic 

 pleurites reddish orange; w^ngs with a brownish tinge; no macro- 

 trichiae in the cells of the wing; Sc long, ending opposite r; Rs rela- 

 tively short and straight; veins R. and Rz long and parallel; basal 

 deflection of R^+i very short, in alignment with Rs. 



Male. — Length about 7.8 mm.; wing 7.8 mm. 



Rostrum and palpi black. Antennae black, moderately elong- 

 ated; flagellar segments cylindrical. Head black. Pronotum black, 

 the lateral margins of the scutellum yellowish. Mesonotum reddish 

 orange, unmarked. Propleura and ventral portions of the meso- 

 pleura and metapleura blackish; dorsal pleurites reddish orange. 

 Sternites black. Halteres black, the base of the stem obscure 

 orange. Legs with the coxae and trochanters black; remainder 

 of the legs black, the extreme bases of the fore femora a little bright- 

 ened. Wings with a brownish tinge; costal and subcostal cells and 



