70 Pysche [April 



which is paler and brighter toward the mouth." The two descrip- 

 tions of Walker may really refer to the same species, assuming 

 that the brown spot on the knob of the halteres was overlooked 

 in glaber. 



Walker's alboflorens seems to approach pirata, having infus- 

 cated halteres and unspotted wings, but so many characters 

 are omitted or vaguely mentioned that a decision is impossible. 



His viridiflos has been identified with my intentus, but as I 

 understand the expressions used, it is much more nearly related 

 to aestuum, a widely different species. At least it is a small 

 eastern species with the wings pale at the base. 



These conclusions will show the uselessness of trying to "do 

 something" with Walker's names. If anything, I have gone too 

 far in assuming that I have identified one species. An exam- 

 ination of Walker's types is the only process that will settle the 

 matter; even that will have only a bibliographical value, and 

 will not advance entomology in the least, assuming that we already 

 know all of his species under some name, which is highly prob- 

 able. I have heard of one entomologist who in recent years 

 did in fact examine a part of Walker's types of Dolichopodidse, 

 and who had the self-restraint on coming home to say nothing 

 about what he found, deeming it best not to disturb existing 

 nomenclature. And he is a man who has contributed vastly 

 to entomology in more than one order. 



THE DIPTEROUS GENUS DIOSTRACUS LOEW. 



(PI. 8.— figs. 15-18.) 



By J. M. Aldrich, 

 The University of Idaho, Moscow, Ida. 



The genus Diostracus was founded by Loew in his Neue Beitrage, 

 VIII, 43, 1861, and redescribed in Monographs, II, 120, 1864; 

 the entire second notice is merely a translation of the first, both 

 as to the genus and the single species, with the addition of one 

 or two unimportant comments. ^ The typical and sole species, 

 prasinus, was collected by Osten Sacken in New York, presumably 

 near New York City. It has apparently not been collected since 



> Note. — On page 122 of the monograph, the expression regarding the middle tarsi, " the 

 first joint about as long as the other three taken together," should have been translated "the 

 first joint about as long as the following three," etc. 



