18 PROCEEDINGS OF THE ACADEMY OP [1886. 



trees in a woods near Philadelphia. It is very active, quick and 

 difficult to secure. I believe it represents a group entirely new 

 to our fauna. 



EXPLANATION OF PLATE I, 



Fig. 1. Psocus texanus var. submarginatus. 



2. " Leidyi. 



3. Ccecilius nubilus. 



4. Head. 



5. Denuded fore wing and thorax. 



6. " hind wing. 



7. Fore wing covered normally with scales. 



8. Tarsus. 



9. Forms of wing scales greatly magnified. 



of Echmepteryx agilis. 



