308 S. W. WILLISTON. 



Catalogue of the Described Species of South 

 American SYRFHID^EI. 



BY PROF. S. W. AVILLISTON. 



A catalogue of the South American species of Diptera is very 

 much to be desired. One was begun, in an excellent way, recently 

 by Lynch, but, unfortunately its progress has been interrupted, and 

 its plan only comprised the Southern fauna. There is a vast deal of 

 Avork yet to be done before any real list of the South American spe- 

 cies is possible, for many synonyms will have to be cleared up, and 

 most of the early described species must be recognized, — a no incon- 

 siderable task — and redistributed in the modern genera ; neverthe- 

 less, a preliminary catalogue will give us a sketch of the fauna, — 

 an indispensable one — from which many lines must be rubbed out 

 and many more filled in before the picture becomes at all complete. 

 As a contribution towards this end, I offer the following list of the 

 South American Species of Syrphidae. Little can be done in such 

 a work save compile, but I have spared no pains to render the com- 

 pilation complete, and have made such distributions as a careful 

 perusal of the descriptions and a tolerably full knowledge of the 

 North American forms have suggested. It should be distinctly un- 

 derstood, however, that such distributions and remarks as I offer have 

 only, in general, a negative value. 



About three hundred names have been given to the South Amer- 

 ican species, distributed among about forty genera. About the same 

 number of species are actually known to occur in the United States, 

 located under nearly sixty genera, so that one may safely say that 

 less than half of the actual fauna of South America in this family 

 is yet known. 



But little can be ventured on the general facies of the fauna based 

 on descriptions alone, yet I would direct attention to some points of 

 interest that have impressed me from a perusal of the literature. 

 The Volucella, Eridalis and Microdon groups appear to be unusually 

 predominant. Undoubtedly many of the names are synonyms, still, 

 enough must remain to indicate a proportionally far greater abun- 

 dance of these forms than exists North of Mexico, though their 



