80 Annals Entomological Society of America [Vol. VIII, 
Following are the species collected by myself in the different 
regions in which I have lived: 
Collectedtini Souths Dakotas 74:seasonssser serene eee ees 35 
At Lawrence, Kans., first half of 1 eeean GUC Daa enka an a Oe ee 19 
In ‘Idaho, 20'seasonss)o vecache <sioe ee eee ee are SOE nr: 91 
IniCalitormiaysirst-nalmonl90G samen cee etee 21 
In Indiana, 114 SEASONS) ec Behan lhs oo Serie ee ee eee 64 
The following figures show something about the relative 
abundance of species: 
Represented by ‘one specimen: 32, 80 42 cma scien a nee eee eee 66 
By! two "Specimens were: «ly. ae ee ee ha eee oe eee 24 
By; Ghreetspecimens. fees ee ele tee ee 23 
By four specimens. crc ccicte a ee ery eer eit ie ee 21 
By, five SPecumens pr c1 ee eet eee ee eet 11 
By ASixiSpeCimens fi sctomck. eee anes Oe ER eee 13 
By \S@ven Specimens ny. 302 Mah vecatyoupo eee eae oa hehehe eee Mier 11 
By eightionmmoresspecimensissh ane eee eae ee ieee 63 
From the figures just given, it appears that about 25% 
of the species are represented by a single specimen, an equal 
proportion by eight or more, and that the other 50% fall be- 
tween these extremes. The strikingly large number represented 
by a single specimen may be in part explained by the fact that 
my entomological friends have sometimes favored me with a 
rarity of which they could spare but one: Professor Melander 
has in fact often divided with me when he had but two speci- 
mens. So I re-examined the 66 cases, and found that only 41 
were collected by myself, and 25 by others. 
During all the period of my collecting I have been trying to 
get long series, especially in recent years. Therefore it seemed 
surprising that I could show eight or more specimens in only 
63 species—the more so as in many of these I had only found the 
insect a time or two in all my experience, as in Dichocera lyrata 
Will., Paradejeania rutilioides Jean., and others. Immediately 
the question arose. How many really common species of 
Tachinide occur in the United States, and which are they? 
Taking my 63 species as a tentative list, I asked Messrs. C. 
W. Johnson and W. R. Walton to make similar ones, enumerat- 
ing the species which they had found either generally or occasion- 
ally common; Mr. Johnson named 52 species and Mr. Walton 
71. About the same time while doing some work in the Illinois 
collection at Urbana I listed 29 named species which were repre- 
sented by eight or more specimens; and on a brief visit to 
