NO. 1719. TYPE-SPECIES OF AMERICAN DIPTERA—COQUILLETT. 501 



almost incredible number of two-hundred and forty-five new species 

 (so-called), which he distributed into five (imaginary) new genera! 

 And this is only one sample from among the many cases.** 



In one instance 1 have difi'ered with the authors of the Katalog in 

 the generic assignment of one species, Tij»da ciilielfoTnds De Geer, 

 which these authors place in the genus Corethra^ but which there is 

 every reason for believing belongs to the preceding genus, Mocldonyx. 

 The breeding of this and related species by Meinert, his reference of 

 the present species to Mochlonyx, and the confirmation of such reference 

 b}' von Roder are set forth in my article in the Canadian Entomologist 

 for July, 1903. I recently wrote to Dr. J. C. H. de Meijere, the 

 leading dipterologist of Holland, for an expression of his opinion on 

 the subject, and under date of September 28, 1908, he wrote me, 

 entirely corroborating this reference, saying, "As to Corethra 

 culiciforinis De Geer, it is my opinion that Meinert has demonstrated 

 with certainty that this gnat is a Mochlonyx.^'' The reference of this 

 species in the Katalog is therefore clearly erroneous. 



In most cases subgeneric names have been thrown into the synonymy. 



In the accompanying list, the writer has personally examined the 

 original references with the exception of a small number, the data of 

 which were obtained at second hand, such genera being indicated by 

 an asterisk (*). The references in regard to the genera founded by 

 Clark in his Essay on Bots (1815) were kindly communicated to me 

 by Mr. E. E. Austen, of the British Museum, while those from 

 Berthold's Natiirliche Familien des Thierreichs (1827) were furnished 

 to me by Mr, E. T. Cresson, jr., of the Academy of Natural Sciences 

 of Philadelphia, and to both of these gentlemen my thanks are due. 



Names of genera which are considered valid by the best authorities 

 are printed in black-face type, but several of those so indicated are to 

 be considered as such oni}^ from want of authoritative knowledge on 

 the subject. Synonyms and homonyms are printed in italicH.^ 



Although the preparation of this paper has extended over many 

 years, and every opportunity has been taken to ascertain the earliest 

 founding of each genus and the first designation of a type-species for 

 the polytypical genera, still it is possible, or even probable, that some 

 earlier records have been overlooked, and the writer will be under 

 obligations to anybody informing him of such previous records. 



oThe Katalog appears to be very complete, except that it omits most of the 

 genera of the Anthomyiidfe and Acalypterse founded by Lioy in the Atti Institute 

 Veneto, ser. 3, vol. 9, 1863 and 1864. The greater number of the genera founded by 

 Meigen in his Nouvelle Classification des Mouches a deux ailes (Diptera L.), 1800, 

 are also omitted; there is a reprint of this paper, with comments and synonymy, by 

 Mr. Friedrich Hendel in the Verh. k. k. Zool.-Bot. Ges. Wien, vol. 58, pages 43 to 

 69, 1908, which I have made use of in the present paper. 



& The generic names are arranged alphabetically, for easy reference. An index to 

 the species is appended to this paper. 



