42 



and to estimate how far isolation lias been the cause of the 

 origin of species. 



Personally I believe that ''isolation", together with the com- 

 parative absence of ^'Natnral Selection", owing to the simple 

 conditions of the biological environments, has been the chief 

 agent in the production of species of onr insect fauna. 



jSTote : — The above notes were written before I had the 

 pleasure of reading Dr. E. C. L. Perkins' "Introduction" to 

 the Fauna Hawaiiensis. It was of great interest to me to read 

 his conclusions, founded upon so detailed a study of the insect 

 fauna, on several of the subjects that I have touched upon. One 

 of the great values of this work is that it is the first time that 

 an isolated tropical island, or group of islands, has been anything 

 like thoroughly worked and then analyzed. The results are of 

 great value, the volume forming the most important of recent 

 contributions to biology. Those who have the pleasure of a per- 

 sonal acquaintance with the author regret that he has not more 

 fully entered into many of the questions discussed, and drawn 

 more fully from his wealth of observations, in a manner that 

 makes his personal discussion of these subjects so interesting. 



On Some Derbidae from Formosa and Japan.* 



BY F. MUIR. 



During a short trip to Formosa in December, 1913, the 

 writer was only able to get three days collecting in the forest, 

 one of which was wet. It was therefore not possible to do very 

 much work, but several new Derbidae were among the Homop- 

 tera. Thanks to the kindness of Messrs. I. jS[itobe, M. Maki 

 and M. Ishida, he was able to procure several interesting speci- 

 mens, and to examine others. Besides the species mentioned 

 below there were also female specimens of three species of Rlio- 

 taim, one Goneokam near to pulluni, one Sikaiana and one Her- 

 pis. This indicates that when more fully worked the Derbidae 

 of Formosa are likely to be numerous. 



Thanks are also due to Prof. S. Matsumura for the loan of 

 certain Japanese specimens. 



The types of the following new species are in tlie collection 



* This contribution from Mr. Muir was received at a later date, but 

 it seems desirable to publish it at this time. — Ed. 

 Proc. Haw. Ent. Soc, III, No. 1, September, 1914. 



