56 ENTOMOLOGICAL SOCIETY 



in preference to the valid ones. The name of the genus, or spe 

 cies as imposed bv its first describer is a matter of much historic 

 and scientific moment ; what any person's opinion is as to what 

 the name ought to have been is a matter of no importance, and 

 belongs rather to the realm of fiction than to pure science. 

 Students in this country almost without exception are agreed that 

 only in the case of preoccupation is there a valid excuse for 

 changing the name of a genus or species, and then, in the case 

 of a genus, the name to be changed must be identical letter for 

 letter with the earlier name. 



Shortly after the advent of Dr. Williston upon the scene, quite 

 a number of our students began to seriously study our Diptera 

 and to record the result of their studies in our various journals 

 and other publications ; in fact, nearly all that has been published 

 on our species within recent years has been the work of our own 

 students. This is certain to result in a better understanding of 

 these insects than was possible'under the old regime, since it must 

 be apparent to all that the student who studies his subjects in the 

 field as well as in the laboratory, and who is in a position to col 

 lect the specimens in large numbers, will obtain a more correct 

 idea of the limits of a species and is also in a position to more 

 accurately interpret the older descriptions which relate to his 

 fauna, than any student in a distant land. This latter fact is 

 clearly set forth in a comparison of two monographs which deal 

 with our Diptera, the one written by Doctor Loew, an author 

 who had never even visited our shores, the other by Doctor Willis- 

 ton, who was born and brought up among the objects of which 

 he wrote. In the first work, a " Monograph of the Dolicho- 

 podidse," of the 60 descriptions of species from the United 

 States published by previous authors, only 8, or less than one- 

 seventh of the entire number, were recognized by Loew, while 

 the remaining species he described as new. There is, of course, 

 no grounds for doubting the fact that a large proportion of the 

 latter are identical with those described by the older authors, and 

 consequently these species have ever since been sailing under 

 false colors, while their valid names have been permitted to encum 

 ber our lists as a useless, meaningless mass, and thus they must re 

 main until some conscientious student from this country again 

 gives this family a careful revision, as a result of which a large per- 



