OP WASHINGTON, VOLUME XIII, 1911. 159 



got and puparium. To this family Macronychia is now 

 known to belong, and in spite of its divergent facial plate de- 

 velopment I believe that it will be found to exhibit the maggot 

 characters just mentioned. It represents an extreme shorten- 

 ing of the facial plate in the sarcophagid stock already begun 

 in the paramacronychiine and especially noticeable in the 

 miltogrammine flies. 



Macronychia is thus no longer tenable as the type of the 

 family which I have called, in deference to Brauer, the Ma- 

 cronychiidse, though realizing that Megaprosopus is the real 

 type of the family. This is a natural family group distin- 

 guished by the shortened cestrid type of facial plate and the 

 noticeably reduced mouthparts, combined with the presence 

 of true abdominal macrochaetae. The exclusion of Macrony- 

 chia makes the group a more natural and easily defined one on 

 external adult characters. Aulacocephala perhaps belongs 

 here, and Neophyto probably goes in the Sarcophagidae. As 

 Megaprosopus is typical of the group, the family may now 

 properly be called the Megaprosopidae. 



In a paper now in preparation I am discussing family 

 characters and reviving both the Sarcophagidae and Dexiidae 

 as families, though in a new sense, the Sarcophagidae stand- 

 ing as above outlined, and the Dexiidae forming a group with 

 a facial plate, of which Dexia is typical. The possession by 

 Macronychia of the megaprosopid type of facial plate and the 

 double-sac type of uterus seems to indicate that the latter 

 specialization is of longer standing than the shortening of the 

 facial plate. Macronychia and its allies appear to be double- 

 sac uterus stock that has developed the shortened facial plate 

 by parallelism. The same parallel development shows a be- 

 ginning in certain muscid if not tachinid stocks, as now re- 

 stricted, and has proceeded far in the dexiid stock. It has 

 progressed farther in this part of the sarcophagid stock. We 

 thus find a successive shortening of the facial plate from the 

 phasiid through the muscid, tachinid, dexiid, sarcophagid, and 

 megaprosopid stocks to the cestrid type. This specialized facial 

 shortening now seems to postdate the primary differentiation 

 of uterine specialization into double-sac and coiled-gut types. 



The Brazilian Pseudogametes and the Siberian Micro- 

 cephalus both appear to be remnants of an old mesembrinine 

 stock that has acquired a strong restrid facies. Both have the 

 mouth-parts much reduced and show evidences of a tendency 

 toward a shortening of the facial plate, which is of very pe- 

 culiar structure, while the cheeks are wide and concave. The 

 well-developed antennae have counteracted the tendency to- 



