150 
K. OGUMA. 
9. P. dorothea Williamson Loo-Choo, Formosa. 
10. Mnais tenuis Oguma Formesa. 
11. Mcrrobasis ehinensis Linnnus Loc-Choo?, China, E. India. 
12. Eupbaea formosa Hagex Foemosa. 
13. E. yayeyamana MatsumueA. Loo-Choo. 
14. Bayadera hyalina Selys Formosa. 
15. Rhynocyphci 14-maeulata Oguma Bonin Islands. 
16. R. ogasawarensis Matsumura Formosa, E. India. 
17. Micromerus lineatus Burmeister. 
All of the palaearctic species exhibit wide ranges of distribution in 
Japan proper, except the first which has not yet been fuiind in Hokkaido, 
most of them being noted for their beneficial influence on the rice culture 
as they devour the injurious insects of the rice plants. Of the subtropical 
species Rhynocypha ogasawarensis occurs in the Bonin Islands only, and the 
rest are found in Loo-Choo and in Formosa. 
The islands of Loo-Choo are of importance as regards the distribution 
of dragonflies, as in the case of other insects, inasmuch as they form the con- 
necting link or stepping stones between Formosa and Japan proper. In 
Loo-Choo are found many species of this family which are also found in 
Formosa, but it is noteworthy that there is no species common both to these 
islands and to Japan proper. 
The Formosa Strait on the other hand seems to form no barrier in the 
distribution of Calopterygidae, since the species are most frequently met with 
in Formosa are also found upon the Asiatic continent. The channel called 
Bashi Channel which spa rates Formosa from Philippines however acts quite 
contrary, as far as this family is concerned; one is not able to find even a 
single species common to both islands' 
Though tiny in area, the Bonin Islands widely scattered in the Pacific 
Ocean are also famous in consequence of their peculiar fauna, since Pryer 
collected the pretty butterfly, Lycaena ogasawaraensis during his stay in Japan. 
I have two of the most peculiar species of dragonflies from those islands, one 
of them belonging to the family Calopterygidae. The demarkation line 
which separates Loo-Choo from Kiushiu should be extended estward and 
