REPORT ON A COLLECTION OF JAPANESE DIPTERA, PRE- 

 SENTED TO TIIIO U. S. NATIONAL MUSFJUM BY THE 

 IMPERIAL UNIVERSITY OF TOKYO. 



By I). W. COQUILLETT, 



Jlonoraiy (Jimtodian of Ihe iJiptera. 



The colloctioii of T)ii»teia presented to the U. S. Niitional Musenin by 

 the Iini)eriiil University of Tokyo, Japan, thronj^li Piolessoi- Mitsukini, 

 contains (129 specimens, representing? 124 species, which ;ire distributed 

 in <S.) genera and 2() (iitfeient families. Of these 124 species, 12 weie 

 originally described from .lapanese specimens; of theothers, although 

 described from other countries, have heretofore been reported as occur- 

 ring in Japan; of the remaining species, 52 were described from other 

 countries than .lapan and have not before been recorded from that 

 country, while the remaining 54 species, or almostone-half of the entire 

 number, are considered new to science and aieduly characterized in 

 the following pages. 



As a whole, the species represented in this collection show a very 

 close relationship to the fauiui of Europe. Indeed, <piite a large |)er- 

 centage of the species are identical, while others so closely resemble 

 Euro]>ean forms that it becomes extremely didicult for one to decide 

 the (piestion of specific distinctness. A few species have extended 

 their range northward from Malaysia or the East Indies, but these are 

 not 80 numerous as one would be led to exi)ect would be the case. 



In addition to the species represented in this collection, an even 50 

 si)ecies have also been recorded from Japan ; 35 of these were originally 

 described from Japanese specimens. Assuming that no error has been 

 made in these references, this will make a total of 174 species of Diptera 

 now known froui Japan — a ridi(;ulously small number, which will no 

 doubt be incn^ased at least fivefold when the Fmpire is thoroughly 

 explored for these and the other oi ders of insects. Baron Osten Sacken 

 has recorded 250 species of Diptera from the Philippine Islands, and in 

 addition to these, 51 species have been re])orted as occurring in these 

 islands, making a total of 301 species. We should reasonably exi)ect 

 three or four times this number from a country so fertile and varied as 

 Japan. 



Proceedings U. S. National Museum, Vol. XXI— No. 1 146. 



:m)1 



