SHALLOW-WATER FAUNA OF THE TROPICS. 81 



a year, in constant relation with a particular 

 phase of the moon, and lasting on each occasion 

 only a few minutes in time, is not the only note- 

 worthy feature of the animal. 



The Palolo worm, as it is caught, varies in 

 length from an inch to a foot or more, and is 

 about a quarter of an inch in breadth, but it readily 

 breaks up into pieces when handled. It is com- 

 posed of numerous rings or segments, each pro- 

 vided with a pair of processes bearing bristles, 

 but there is no head. Astonishing as it may 

 seem to those unacquainted with the natural 

 history of Worms, it is nevertheless a fact that 

 when the Palolo swarms it leaves its head behind 

 among the Corals, where, in all probability, it 

 regenerates a new body. This accounts for the 

 fact that while the body of the Palolo is fre- 

 quently brought home to our Museums in Eng- 

 land, its head is a rarity. The colour of the 

 Worm varies very considerably. The pieces 

 bearing eggs are usually of some shade of green, 

 hence the specific name Palolo viridis that is given 

 to it by scientists, but the males are usually 

 white. In connection with the appearance of the 

 Worm there is a curious statement that once in 

 every four years it is exactly one lunar month 

 late, so that the time of year of its occurrence is 

 constant. The natives are also forewarned of the 

 advent of the Palolo worm by the movements of 

 I the land Crabs, which, it is reported, come down 

 from the fields and forest a few days before the 

 Palolo feast and plunge into the sea. 



The precise habitat of the Worm when it is 

 not swarming is still a matter of some doubt. 

 F 



