THE TRICHOPTERA 79 



excessive and during the evening hours. Its wings 

 are now gauzy and its body lighter and more brilliant 

 in colour. It is easily recognized as it soars, floats, 

 and sinks in the ambient summer atmosphere. 



The following are some of the well-known forms of 

 the Ephemeridaa : Olive Duns, Duns, Blue Duns, 

 Autumn Duns, Blue-Winged Olives, Iron Blue Duns, 

 Red-Quill Duns, Red Spinner, Jenner Spinner, May- 

 fly, March Brown, etc. 



THE TRICHOPTERA, OR CADDIS-FLY 



These insects, unlike those of the Ephemeridse and 

 Perlidse family, undergo a distinct metamorphosis 

 during their sub -aqueous existence. 



The larvae of the Caddis-fly may be divided into two 

 distinct classes. The one class, after leaving its egg, 

 spins a cylindrical sheath, which forms its future home, 

 and to which it attaches small stones, sand, wood, 

 etc. ; these cover and mask this case, and at the same 

 time act as ballast. The case thus forms an armour- 

 like protection against enemies. The larva uses this 

 sheath as a movable residence, and from the open 

 end its head, thorax, and legs protrude and provide 

 the motive power, the weak and maggot-like body 

 being always enclosed and protected by the armour- 

 clad case, which it drags about from place to place. 

 After various enlargements to suit the growing condi- 

 tion of its body, the larva enters and partially closes 

 the open end of its case ; it then commences its pupal 



