1910} Melander — The Genus Tachydromia AT 
name of the original genus to such restricted genus or subgenus as may 
be judged advisable, and such assignment is not subject to subsequent 
change.” Dr. Stiles! has given a personal ruling further that “If an 
author, in publishing a genus with more than one valid species, fails 
to designate or to indicate its type, any subsequent author may select 
the type, and such designation is not subject to change.” Although 
this is a personal opinion its soundness is apparent. With these cita- 
tions, we may take up the subsequent history of Meigen’s Tachy- 
dromia. 
Meigen’s early conception of the genus was the same as our present 
idea of the subfamily Tachydromiinae, or even the combined sub- 
families 'Tachydromiinae and Hemerodromiinae, and in this he was 
followed by the earlier writers, such as Fallén. In 1822 in the third 
volume of the Systematische Beschreibungen Meigen separated from 
Tachydromia the genera Hemerodromia and Drapetis. The remaining 
Tachydromias he grouped into two divisions, A and B, with his. 
crmicoides in A. and his cursitans in B, but still retaining all in the 
genus Tachydromia. Macquart in 1827 bestowed the name Platy- 
palpus on division B which was the larger group, keeping the name 
Tachydromia for the first group, but Meigen not knowing this renamed 
the first division Tachypeza, to retain the original name for the larger 
division. ‘This change was published in 1830, and later he refused to 
adopt Macquart’s name because he thought his own ideas were better. 
In a paper in the Zeitschrift fuer Entomologie, published in Breslau 
in 1863 Loew discussed the question at length and following Meigen 
discarded the name Platypalpus because it is a poorly formed com- 
pound of Greek and Latin. For the larger group, or those species 
related to cursitans, he retained the name Tachydromia. The re- 
mainder of the genus he subdivided into Tachypeza, Tachista, Dysa- 
letria, and Phoneutisca, bestowing the name Tachista on those species 
grouped about cimicoides. ‘The majority of the prominent European 
dipterists have adopted this view principally out of deference to Meigen 
and Loew. 
The date of publication of the name Platypalpus is certain, and its 
designation is unquestionable. We have therefore no recourse but to 
accept it as a valid name. ‘To this genus belongs the cursitans of 
Meigen’s original Tachydromia. Eliminating this species, the cimi- 

1 Bull. 24, Hygienic Laboratory, p. 27 (1905) Rule 10. 
