66 



THE COCKROACH : 



B 



C 



Fig. 31. Tricorythus. Adult larva, with three functional leaflets. The next 

 leaflet in front is converted into a protective plate. X 7. 



A, protective plate of Tricorythus larva, seen from the outside. X 26. 



B, the same from within, showing the attached respiratory appendage. 



C, protective plate of Coenis larva, without respiratory appendage. 



All the figures are copied from Vayssiere. 



