334 Transactions of the Society. 



when the wing closes with a " snap " and remains closed. The 

 converse happens when pressure is applied to return the wing to 

 its former position ; it resists opening up to a certain point and 

 then flies outward through a wide angle. This is apparently due 

 to what may be termed a dislocation of the articulation 14. 



I have been unable to observe any vibration of the wing 

 shoulder such as is apparent in other genera, and the general 

 arrangement of the parts makes it clear that the sound-producing 

 apparatus I have described above cannot be brought into action. 



