INSECUTOR INSCITIiE) MENSTRUUS 119 



but front pair more swollen than hind pair ; hjnd femora and 

 tibiae slightly arcuate ; hair-brushes of middle and hind tibiae 

 extremely long; first and second hypopygial segments about 

 equal in length, both rather elongate. 



The generic name has been on labels in the U. vS. Nat. Mus. 

 collection for many years, and is adopted as very appropriate. 



Tricharcca Thomson, 1868, Dipt. Eug. Resa, 541. To this 

 genus belongs Dexia albicans Walker, 1858, Trans. Ent. Soc. 

 Lond., n. s., IV, 204, Amazon valley. Austen has examined 

 the type and indicated it as Gen. Nov. afif. Sarcophaga, over- 

 looking Thomson's description (Ann. Mag. Nat. Hist., ser. 7, 



XIX, 344). Walker's species appears to be distinct from 

 Thomson's T. scatophagina, Rio Janeiro. 



OxYNOPS serratus Townsend, 1912, Journ. N. Y. Ent. Soc, 



XX, 110-11 equals Hypostena nitkns Coq., 1897, Rev. Tach. 

 63. External characters are given in a forthcoming paper. 



Schisotachina zntincrvis Thompson, 1911, Can. Ent., XIJII, 

 268. It is extremely doubtful that this is distinct from S. 

 convccta Wlk. There is absolutely no constant structural dif- 

 ference outside of the obliteration of the fourth vein. Males 

 of convccta with entire fourth vein show third aristal joint no 

 longer than second, and in one case it is shorter; also the 

 facialia are ciliate only on lower fourth in some specimens with 

 complete fourth vein. Some specimens, as noted by Thompson 

 (ibid., 271), show the apical crossvein much fainter than the 

 rest of the veins, indicating a stage in process of obliteration. 



Dichcetoneiira Johnson, 1907, Psyche, XIV, 9 equals Phyto- 

 MYPTERA Rdi. (1845). Genotypes congeneric. 



Biicordylidcxia Townsend, 1915, Insec. Inscit. Menstr., Ill, 

 41. To this genus evidently belongs Cordyligaster tipuliformis 

 Walker, 1858, Trans. Ent. Soc. Lond., n. s., IV, 205-6, So. 

 America. It is a striking fact that Walker noticed the 

 atrophied tegulse in this form, as witness his statement "alulse 

 whitish, ver}^ small (alulis albidis minimis)," which should 

 vindicate him from the charge of careless observation. The 

 color description given by Walker indicates either a distinct 

 species or a very pale and immature specimen of B. ategulata 

 Townsend. One of the Guatemalan specimens mentioned in 



