126 STARFISH GALLERY. 
The last group of Worms here represented is that of the 
Gephyrea ; with the advance of our knowledge it is probable that 
they will be found to be more intimately allied to the Annulata 
than is now generally supposed ; it will be seen indeed that 
Echiurus has bristles at its hinder end ; Sipunculus is the best 
known representative of the unarmed Gephyrea ; Bonellia is inter- 
esting both from the fact that it owes its green colour to a matter 
closely resembling the chlorophyll of green plants, and from the 
possession by the female of a proboscis, which is protruded from 
the hole in the rock occupied by the worm : the male is very much 
smaller than the female, and is not nearly so well developed. Owing 
to the mode of lighting the Gallery, the visitor may have to shift 
his position several times before gaining a good view of the whole 
length of the proboscis. 
