LAETiE OP WATBE-FLIES. 257 



to become the sub-imago, a landing-stage should be prepared 

 for it — one similar to that recommended for the pupae of the 

 Dragon-fly will do. And i£ the aquarium-teeper is for- 

 tunate, and has arranged matters properly, he will be able to 

 witness not only the interesting sight of the pupa becoming 

 the " green drake," but also the " green drake " developing 

 into the beautiful and graceful Day-fly {Ephemera milgata) 

 (Mg. 157). 



There are three other genera belonging to the family 

 EphemeridcB — viz., Baetis, Braehycercug, and Chen. The imago 

 of the genus Baetis is much like that of the Ephemera, 

 with the exception that it has only two setse instead of three, 



Fig. 157. Day-fly (Ephemera vulgata). 



but the larva of the former is very different from that of 

 the latter. Its head is much broader, blunter, and more 

 sunk in the thorax than is that of the larva of the Ephemera. 

 The legs are also larger in proportion and placed more 

 closely together than are those of the latter insect, and the 

 antennae are much shorter. There are some curious and 

 interesting branchial leaflets attached to the segments of the 

 abdomen, and at the extremity of the body there are three 

 long bristle-like appendages. Its treatment, and that of the 

 larvse of the two genera Brachyeercus and Clo'en, while in 

 confinement should be the same as that of their near relative 

 the larva of the genus Ephemera. The imago of the genus 

 Brachyeercus has two wings and three setse, and that of the 

 genus Clo'en has two wings and two setae. The Day-fly of 



s 



