4 
Siplionophora Rosarum 
portion forming the base and terminating in a more slender part. The 
whole of the surface of this joint is covered with small ridges giving it 
quite a remarkable appearance (Text Fig. 6). The significance of these 
ridges is open to conjecture, but probably they indicate the presence of 
some kind of sense organ. 
The only definite sense organs which S. rosarum has are the eyes, 
