66 K. OGUMA : 



might speculate of its possible relation to the physiological state which 

 leads to the ecdysis* of rectal tracheal gills during the metamorphosis. 



* See my f rmerly published paper: On the rectal tracheal gills of a libellulid-nymph and 

 their fate during the course of me amorphosis. Beri. Ent. Zeitschr. Bd. LVIII, pp. 211-225 

 (1913)- 



