1905.] 3 



Descending at Niederliasli, a few minutes' walk brought us to our 

 hunting ground. It was still too early to look for much, but after 

 our first inspection of the lake, we were disconcerted by the appear- 

 ance of the weather — thunder in the distance, and more than threaten- 

 ings of rain made us think seriously of seeking shelter, and also of 

 the possibility of our having to give up the chase. However, the 

 storm passed off and we returned once more to the lake. Just where 

 we left the road at a little stream, Calopteryx splendens was found, 

 and in the same neighbourhood a few Orthetrum coerulescens were 

 darting about. About the marshy margins of the stream Pyrrliosoma 

 tenellum occurred in a very restricted area, in accordance with its 

 usual habit in Switzerland where Dr. Eis says he has always found it 

 to be very local. Like many of the small Swiss lakes the Metmen- 

 hasler See is approached through a peaty marshy tract (more or less 

 distinct from tlie lake proper), with ponds filled with water-lilies and 

 Utricularia. These are the special haunts of Leucorrhinia, and one 

 or two L. alhifrons were noted, including one which had just emerged. 

 These ponds were also frequented by Eri/thromina najas which 

 received special attention in the hope that perhaps E. viridulum, a 

 species discovered here by Dr. Eis a good many years ago, might 

 also appear ; we were now evidently too early for it. The commoner 

 AgrionidcB were as before strongly represented. Among the larger 

 species, yS/, isosceles again appeared, Anax imperator was more or less 

 common, while Cordulia cenea, Gomphus pulchellus and a single 

 $ Si/mpef rum fonscohmbii were a.ho observed. But Anax parthenope 

 was so long in appearing that Dr. Eis began to doubt whether the 

 seventeen years which had elapsed since he met with the insect, in all 

 the glory of a dominant species, had not seen an important change in 

 fauna of the lake involving the disappearance of its most distinguished 

 member. It was well on to mid-day before its presence was estab- 

 lished, and even then they were dashing about wildly and impossible 

 of approach. At last a ^ was secured, and about the same time my 

 wife caught a fine pair. They frequented almost exclusively the lake 

 proper, and could be distinguished easily from the other Anax by the 

 darker abdomon with bright blue base. Further attempts to capture 

 more proved futile at the time, so we stopped operations and went on 

 to the village. Eeturning to the lake in the afternoon we found their 

 demeanour altered. A gentle breeze was blowing up the lake, and 

 instead of flying madly about, they now faced the wind poising on 

 rapidly vibrating wing — striking objects with their brilliant blue basal 

 band distinctly visible in the bright sunshine. A favourite position 



