PREFACE. XIII 



syuonjinies which I give, but to form an opinion for tliemselves. 

 For synonymies, ^Yhich are borrowed from other authors, the 

 authority is always quoted in brackets [j; synonymies without 

 Kuch a quotation, are my own. 



Nomenclature and priorities. Headers of the Catalogue will 

 often find, among the synonyms, names which, according to rule, 

 should have the priority, being of earlier date than the adopted 

 specific name. In such cases , I have discriminated between my 

 roles of a monographer and of a catalogue-maker. In those 

 families, which I have described monographically (T'qmlidae hrevi- 

 jmJpi , Tabanidae, the genus Syrplius), I have settled the syno- 

 nymy in a way that, as far as my knowledge goes, I consider 

 as final. In other portions of the Catalogue, the question con- 

 stantly arose, whether to substitute uncertainty, for certainty, 

 that is, whether specific names by Loew, the types of which 

 exist in the collection of the Museum of Comparative Zoology, 

 had to be replaced by their more or less xoroliaUe synonyms 

 from Messrs. Macquart's and Walker's writings? In such cases 

 I have generally given Dr. Loew's names the first place, leaving 

 the question of priority open for the monographer of the future. 

 In the few cases, where I have acted differently, I have given 

 my reasons in a note. Likewise , as a catalogue-maker , I have 

 not replaced current names by some older ones, which I happened 

 to have discovered ; the latter will be found in the synonymy. 

 Thus, in looking over the Banksian collection in London, I found 

 that the undoubted type of Fabricius's Laphria grossa, is nothing 

 but the common X. tcrgissa Say. In the same way, Clirysops 

 varlcgatus Degcer, is the older name for the wellknown Clirysops 

 costatus from Cuba, and Milcs'm virginiensis Drury, the earlier 

 name for If. ornata Fab. All these names, not being current, 

 will be found in the synonymy. 



Considerations of the same kind have influenced me in the 

 matter of generic names. The name Anastrcpha Schiner, although 

 earlier than Acrotoxa Loew, will be found among the synonyms, 

 because it belongs to the future monographer of the Trypctklae 

 to make changes in an existing monograph. I have but sparingly 



