The Structure and Habits of Spiders. 93 



hard appendages to support and guide the pal- 

 pal organs when the latter are thrust into them. 

 These parts, like the palpal organs, furnish con- 

 venient marks for distinguishing species. The 

 spermathecae, E, vary but little in shape in 

 different spiders ; but the tubes H and D are 

 often lengthened, and twisted into shapes near- 

 ly as complicated as those of the palpal organs. 



Fig. 50. 



Fig. 50 is the epigynum of a small Theridion, 

 where the arrangement of parts can be very 

 distinctly seen. E, E, are the spermathecae ; 

 H, H, the tubes opening into the oviduct ; and 

 D, D, the tubes opening outward. Fig. 5 1 is 

 the epigynum of another closely allied species, 

 where the tubes D, D, are very much elongated 

 and twisted up, corresponding to the long dis- 



