10 REV. A. E. EATON ON EECENT EPHEMERID.E OR MAYFLIES. 



within the bottle a piece of paper, secured from shaking about, to afford foothold to the 

 captives. A woollen wrapper round the bottle, and three or four drops of water upon the 

 paper, meet these requirements ; and in very warm weather the bottles can be carried in 

 a mat basket. Subimagines of certain genera issue only at particular times of the day ; 

 as a rule, the afternoon and evening are the best periods for collecting them. In the 

 morning specimens harbouring amidst branches of shrubs and trees overhanging streams 

 can be procured by beating into the net. Nocturnal species may advantageously be 

 looked for in spiders' webs, and on lamps, adjacent to rivers ; and wherever such lamps 

 happen to be close to white walls or placarded hoardings, numbers of specimens are apt 

 to be attracted by the illuminated surfaces. Subimagines of Bmtis and sundry other 

 genera may frequently be found clinging to Sparganium and grass at the borders of 

 streams, a few inches above the level of tlie water. 



Many species tliat fly by night appear on the wing before dark. They are most of 

 them short-lived. The ordinary flight of Oligoneuria is rapid, the insects sweeping 

 swiftly to and fro, far up and down the stream, with flurried bustling movements, very 

 similar, indeed, to those of LeptoceridjB, the females for the most part close to the surface, 

 and the males a few feet above it, while now and again a female hurries aloft pursued by 

 a jostling throng of admirers amidst whom she very soon sinks down again encumbered 

 towards the water. Upon occasion, however, they behave differently. During one or 

 two nights only in the course of the season, in favourable weather, innumerable multi- 

 tudes of these flics issue after sundown from the river, filling the air, like snowflakes in a 

 storm, to a very considerable height (M. Albert Miiller observed some at an altitude of 

 500 feet above the E,hine at Basle), and advancing steadily in one direction. Species of 

 other genera, such as Falingenia and Polymitarcys, have a similar habit of swarming, and 

 so also have certain kinds of Ephemera and Hexagenia. Ccenis has been observed in 

 East Central Africa flying in dense clouds that resembled smoke in the distance. 



Most of the Ephemeridte couple during flight, the male lowermost. Darting at his mate 

 from below, and clasping her prothorax with his eloutjated fore tarsi (whose articulation 

 with the tibia is so constructed as to admit of supination of the tarsus) he bends the 

 extremity of his body forwards over his back, grasps with his forceps the hinder part of 

 her seventh ventral segment, and with his outer caudal setse embraces her sixth segment. 

 These two setae exhibit near their origin a strongly marked articulation, where they can 

 be deflected abruptly so as to lie forwards over the back of the female parallel with one 

 another betvt^een her wings. Meanwhile the couple gradually sink, the female not being 

 quite able to support herself and mate ; and by the time they reach the ground, if not 

 before, their connexion is usually terminated, although a pair of Ecdyurus has been seen 

 by me to maintain union effectively as long as six or seven minutes after they had come 

 to rest. Soon after their disengagement the male flies away to resume his interrupted 

 gambols (being prone to polygamy), and the female after resting awhile repairs to the 

 water to lay her eggs. Many of the females are polyandrous. 



The male of PaUngeuia has very short fore legs ; and he is mated, not in mid air, but 

 upon the river amidst crowds of rivals, who pile themselves up upon him and his sur- 

 roundings until he is overwhelmed by a large struggling mass of them floating dowji the 



