SVXOFS/S. IX 



and pupa, 90. Pteronarcys, 90. Tracheal gills of larval Pte- 

 ronarcys retained in the adult, 90. Resemblances of the larvae of 

 Plecoptera to those of Ephemeridoe and Thysanura, 90, 91; re- 

 semblances of the adults to Platyptera, 91. Aquatic larvae of 

 orders II.-IV., 91. 



OKDEK A . — PLATYPTERA. 



The Termitidre structurally dift'erent from the Formicidse, 92. 

 Effects of social habits upon structure, 92, One cause of color, 



92, 93. Sessile abdomen of Termites and pedunculated abdomen 

 of Hymenopterous ants, 93. Mouth parts of worker and sol- 

 dier, 93; difference in structure proportioned to amount and 

 kind of work performed, 93. Arrested development of workers 

 and soldiers, 93, absence of eyes and wings, 93. Presence of 

 wings in males and females, significance of term " Platyptera," 



93. Structure and helplessness of larvae, 94; resemblance to Thy- 

 sanura, 94. Development of larvae into two castes of males and 

 females, 94; caste of complemental males and females, king 

 and queen caste, 94. Colorlessness of Termites correlated with 

 habits, 94, 95. Fritz MUller on Termites of Brazil, 96. Dr. 

 Hagen on habits and destructive work of Termes Jlavipes, 96. 

 Smeathman on African Termites, 97, Psocidae, 97. Structure 

 of body and appendages, 97. Characters of book -lice, 98. 

 Mallophagidae as examples of specialization by reduction, 98. 

 General remarks on the Platyptera, affinities of the Platyptera 

 with the Orthoptera and Dermaptera, 98, 99. 



ORDER VI. — DERMAPTERA. 



Structure of Forhcula, 100, Peculiarities of the wings, 100, 

 significance of term "Dermaptera," 100. Forcep-like appen- 

 dages of the abdomen, 100. Reasons for giving the names 

 Forficula and ear-wig, 100. P^orficulidse of New England, 100. 

 Characters of larva, 100. General remarks on Dermaptera, loi ; 

 generalized structure of ear-wigs, loi. Position of order in the 

 classification, loi. 



