158 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



meut. I have seen exceptional cases, but they are rare." 

 When the maggots are fully developed they are rapidly de- 

 posited. As the maggots approach full development, another 

 set of eggs forms in the ovarioles, and these descend as soon as 

 the uterus has been emptied. I have found the ovaries filled with 

 a set of full-sized eggs and a few perfect maggots in the uterus 

 at the same time, showing that larviposition of one set of 

 maggots was in progress. The leaf-ovipositing and leaf-larvi- 

 positing forms belong in the other category, where continuous 

 and successive development and descent of eggs, development 

 of maggots, and oviposition or larviposition take place, the 

 latter depending only upon the finding of suitable conditions. 



This second group of Pantel corresponds perfectly to my 

 leaf-ovipositing forms, and seems a most compact and well- 

 defined group, embracing all the microtype egg forms known, 

 and easy of definition by dissection. Nevertheless, the indi- 

 cations are that at least some of these groups are of independent 

 origin from the main stock, and it is quite probable that we 

 shall ultimately find that the group is merely a collection of 

 stocks of diverse origin. I have found types of slender, 

 elongate, more or less pointed microtype eggs, as mentioned in 

 my last paper, and many forms with a deep yellow instead of 

 black or gray chorion, none of these having appeared in 

 Pantel's material. 



Group III. Species extruding large and robust larvae 

 known as ordinary flesh maggots. This is the group of the 

 sarcophagine, metopiine, etc., flies and their allies, a very nat- 

 ural one characterized by the double-sac form of uterus, 

 termed by Pantel very aptly a twin-pouch incubator. The 

 author does not distinguish between the cordate and V-shaped 

 types of this form of uterus, which I have pointed out. 



Pantel's dissection of Macronychia agrestis, the type of the 

 genus, makes its reproductive system now for the first time 

 known. The discovery that it possesses, as I had thought prob- 

 able, the double-sac type of uterus calls for an important 

 change in family nomenclature. Since rediscovering for my- 

 self the nature of the sarcophagine uterus, which it appears 

 was described and figured as long ago as 1851 by Dufour, I 

 have felt that the old family Sarcophagidae should be revived. 

 We are now able to separate these forms definitely from the 

 rest of the Muscoidea. Moreover, other important characters 

 indicate their compactness as a family group, notably the 

 uniformly very generalized type of the cephalopharyngeal 

 sclerites of the first-stage maggot and the position of the 

 posterior stigmata at the bottom of an anal cavity in the mag- 



