OF WASHINGTON, VOLUME XVII. l!i:, 41 



NOTE ON THE SPALLANZANIINE FLIES. 



(AUTHOR'S. ABSTRACT.) 

 BY C. H. T. TOWNSEND, Bureau of Entomology. 



The two species Pseudogonia ruficauda Townsend (1892) nnd 

 Cnephalomyia floridana Townsend (1912) are so similar in the 

 adult as to be indistinguishable until one has learned the very 

 slight but constant differences that separate them. Their eggs 

 and first-stage maggots are greatly contrasted, though both belong 

 to the microtype-egg stocks. They represent distinct genera, 

 and the former will become the type of a new genus. They are 

 evidently cases of convergent evolution in the adult, in con- 

 junction wit 1 ! divergent evolut'on in the eirly stages, indicated 

 not only by the egg and first-stage maggot characters but also 

 by the character of the slight external differences of the fly, and 

 have traveled separate paths of development from distinct ori- 

 gins within the Spallanzania group, though no doubt of ancient 

 common origin. On external characters alone, one would un- 

 hesitatingly refer both to the same genus, and a nice discrimina- 

 tion is required to satisfy oneself that they are not the same 

 species. This is a notable case of the early-stage characters 

 constituting an index to the value of the external adult char- 

 acters. Full details will be published in due time, including 

 synopses based on adult characters. From Williston's descrip- 

 tion and two figures of the head, it appears that Acroglossa hes- 

 peridarum Williston does not belong in the Spallanzania group, 

 and that a mistake has been made in labeling the type specimen 

 of that species. 



Two HUNDRED AND EIGHTY-FIRST MEETING, 

 DECEMBER 3, 1914. 



The 281st regular meeting of the Society was entertained by 

 Mr. W. D. Hunter in the Ssengerbund Hall, December 3, 1914. 

 There were present Messrs. Abbott, Baker, Barber, Boving, Busck, 

 Caudell, Coad, Crawford, Cushman, Duckett, Ely, Gahan, Greene, 

 Heidemann, Heinrich, Hunter, Hutchinson, Isely, Knab, Kotinsky, 

 Mclndoo, Middleton, Parker, Pqpenoe, Rohwer, Rust, Sanford, 

 Schwarz, Shannon, Simanton, Townsend, Van Dine, Walton, 

 Webb, White and Wood, members, and Messrs. John E. Dudley, 

 Jr., G. L. Garrison, H. G. Ingerson, R. W. Morland and Mitchell 

 Phillips, visitors. 



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