THE EPHEMEKINiE. 353 



this point, and many other particulars relative to them, 

 are still involved in deep mystery, which time and care- 

 ful observation only will elucidate. We place them in 

 this circle, as its most aberrant group. 



(311.) We now enter our fifth circle, comprising 

 the group of the Phbyganid^, — the majority of which, 

 in their preliminary stages, inhabit the water ; and 

 throughout the whole of which we find a uniformity of 

 texture in their four or two wings, — which peculiarity 

 we quitted in leaving our first circle, the LibellulidcB. 

 The first sub-family of these constitute the Epheme- 

 rincB; the brevity of the lives of which, in their perfect 

 state, have furnished moralists with a comparison for 

 the shortness and vanity of the life of man. In many 

 particulars of structure, these insects bear a strong af- 

 finity to the first sub-family of our first typical circle of 

 the Neuroptera, viz. the LibelluUnce. Like them, tliese 

 are destitute of palpi ; and they have short, subulated 

 antennse, and they likewise exhibit a large developement 

 of the eyes : in their wings, however, we observe a con- 

 siderable difference ; for in the present sub-family, the 

 secondary wings are considerably the least in size ; and, 

 as a necessary consequence, there is a smaller develope- 

 ment of the metathorax, — the reverse of what we find in 

 the LibellulincB ; but these wings are always expanded, 

 and never folded. In the EphemerincB, we observe con- 

 siderable sexual discrepancies in the length of the anterior 

 elongated legs, which are protruded forwards, and evi- 

 dently serve, as in some of the gnats, for organs of 

 touch ; and the apex of their abdomen is furnished with 

 two or three lengthy and articulated setae. There is 

 much resemblance between the larva and the perfect 

 insect. These larvse breathe by branchise, and they oc- 

 cupy burrows formed in the mud of the banks of the 

 streams wherein they dwell : they feed upon the larviB 

 of other insects, or animalcule, which they bring within 

 their reach through the motion given by their branchiae 

 '• to the water : they possess very large mandibles, which, 

 besides assisting them in the capture of their prey, 



A A 



