1897.] Mr Perkins, Notes on some Hawaiian Insects. 373 



Monday, 6 December, 1897. 



Mr F. Darwin, President, in the chair. 



The following were elected Fellows of the Society : 

 Mr A. S. Ramsay, M.A., Fellow of Magdalene College; Mr 

 W. M. Fetcher, B.A., Fellow of Trinity College. 



The following were elected Associates of the Society : 

 Mr J. Zeleny, Mr H. A. Wilson, Mr G. H. Shakespeare, Advanced 

 Students of Trinity College ; Mr J. H. Vincent, Advanced Student 

 of St John's College ; Mr P. Langevin, Advanced Student. 



The following Communications were made to the Society : 



(1) Notes on some Hawaiian Insects. By R. C. L. Perkins. 



Amongst the most important representatives of the Order of 

 Neuroptera in the Hawaiian Islands, are the dragon-flies of the 

 genus Agrion. Several species are found on all the more import- 

 ant islands of the group, and the range of many of them extends 

 over several islands ; wherein they differ from the greater part of 

 the endemic insects, which are for the most part confined to a 

 single island ; or to one or two of those which lie most closely 

 together. At the same time, when a series of examples of a 

 species from different islands is compared, certain more or less 

 constant differences are often observable, especially as regards 

 size. 



But the most interesting facts relate to the earlier stages or 

 nymphs, which are aquatic and carnivorous. Excluding these 

 dragon-flies and a few r water-beetles, the insect fauna of the 

 streams and pools is almost non-existent. The Ephemeridae, 

 Perlidae, and Trichoptera, usually so numerous, are entirely un- 

 represented in the Islands, although the mountain streams, rising 

 at high altitudes, with their superb waterfalls, and various 

 temperatures, appear admirably adapted for many of these. It is 

 therefore not a little surprising to find the group of dragon-flies so 

 well represented, and that the individuals are so numerous, being 

 on the whole the most conspicuous of all the endemic insects. In 

 the absence of the groups above mentioned, I believe that their 

 main food-supply comes from without, consisting of such creatures 

 as accidentally fall into the water. Under ordinary circumstances 

 this is not great, but after rain, when the streams rise very 

 quickly, food becomes abundant. When the streams, as is often 

 the case, become nearly dry, large numbers of creatures resort to 



