354 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.43. 



Unfortunately the character of the fu-st-stage maggot of Trixa is 

 unknown. It is possible that it is somewhat similar to that of 

 PTmsio'pteryx. 



Family DEXIID^. 



Snbfanaily DKXIIN".^:. 

 MICROCHiETINA ARIDA Townsend. 



Almugmyia arida Townsend, Ann. Ent. Soc. Amer., vol. 4, 1911, pp. 136, 148; 

 Proc. Ent. Soc. Wash., vol. 13, 1911, pp. 154-155.— TD 3979. 



Length of body, 6 to 7 mm.; of wing, 5 to 6 mm. Numerous 

 specimens of both sexes, Piura, Peru, August 9 to November 4 and 

 later, 1910, on trunks of mesquite. 



Wholly thickly cinereous pollinose, the face and front quite silvery. 

 Frontalia and antennae brown. Cheeks with a light brownish tinge. 

 Thoracic vittse very faint, hardly showing through the thick pollen. 

 The pollen of hind borders of abdominal segments is faintly yellowish. 

 The female lacks median macrochsetae on the first two abdominal 

 segments or has at most atrophied ones, but the male has a median 

 marginal pair on the second segment. Both sexes with the long 

 median pair of third segment subdiscally placed. Anal segment with 

 discal row. The wings are faintly straw-colored on base and costa. 

 Costal spine strong. Apical cell long-petiolate. Male front greatly 

 narrowed at vertex. Third antennal joint in both sexes about one 

 and one-half times as long as second. Claws of male very long. 



Type.— Cat. No. 15197, U.S.N.M. Female, November 4, 1910; TD 

 3979,/. r. s. 



Deposits white maggots in choria where they can reach host. 



This is the type of the genus Almugmyia, which I prefer for the 

 present to leave in Microchsetina. It may be employed, if found 

 desirable, on comparison of the types of the two genera. 



AGLUMMYIA, ne-w genus. 



This genus differs from Almugmyia by having the hind crossvein in 

 middle between small crossvein and apical crossvein, the petiole of 

 apical cell short, end of fourth vein not greatly removed from hind 

 margin of wing, parafrontals and parafacials much narrower, the 

 latter with fine hairs throughout, third abdominal segment with 

 marginal row of macrochaetse. Almugmyia has apical cell with a very 

 long petiole, the hind crossvein much approximated to small cross 

 vein, the bend of the fourth vein far removed from hind margin of 

 wing, the parafrontals and parafacials wide, the latter with a few 

 short black bristles on lower extent near inferior eye-border, and 

 third abdominal segment with onlj^ a median subdiscal pair of 

 macrochsetae besides the lateral pairs. The other characters are very 

 similar in the two genera. Three sternopleural and three postsutural 



