Vol. XII. May, 1907. No. 6 



BIOLOGICAL BULLETIN 



THE SYSTEMATIC AFFINITIES OF THE DIPTEROUS 



FAMILY PHORID/E. 



CHARLES' T. BRUES. 



In a paper on the nomenclature of the dipterous wing published 

 in the current number of Psyche, Professor Williston ('06) has 

 again raised the much vexed question of the relationship of the 

 Phorid?e among the families of Diptera. 



During the past few years I have devoted considerable time 

 to a study of this small and truly remarkable group of flies, but 

 have been unable so far to reach any wholly satisfactory con- 

 clusion as to their proper systematic position. Attempts in a 

 number of directions have each revealed some important if not 

 insuperable obstacle, and I had let the matter rest, compelled to 

 accept, albeit rather unwillingly, the final decision expressed by 

 the late Baron Osten Sacken in the following words : " A real 

 affinity with PJiora does not exist anywhere." 



In the nature of things such a negative opinion on a question 

 of phylogeny can only be tentative, and it is with pleasure that 

 I find the discussion reopened by so eminent a dipterist as Pro- 

 fessor Williston. 



Several entomologists who have given special attention to the 

 group have attempted to reconcile its notable peculiarities of 

 structure with types to be found elsewhere within the order of 

 Diptera, and one has even essayed to connect them with the 

 Aphaniptera which are almost unanimously regarded as forming 

 a separate order. 



The antenna:; and the wings are the organs which offer the 

 difficulties and I shall describe them briefly. The antenna con- 

 sists apparently of a single large globular or pear-shaped joint 



349 



