394 EEV. T. POWELL ON THE STEUCTUEE AND 



the time of .spawning the sea becomes discoloured with tbe eggs 

 for a long way around; and yet there is no corresponding 

 appearance of broken cysts : there are some such cysts to be 

 seen, but nothing comparable to what there should be on the 

 supposition which I am challenging. 



That the sight of these annelids is perfect is evident from the 

 way in which a single specimen will endeavour to escape the sieve 

 with which it is the custom to catch them. Often, when seeing 

 a fine single sjjecimeu approaching, I have put down my sieve, 

 hoping to take it, but generally in vain ; for no sooner has my 

 sieve been jjut into the water, than the animal has made off 

 rapidly in an opposite direction ; and when I have attempted to 

 intercept its flight, it has immediately dodged again and escaped. 



The palolo move through the Avater in different ways : some- 

 times they. are extended nearly at their full length, with but little 

 curvature of their bodies ; their progress is then sIoav. At other 

 times they assume a more serpentine form of progression, and 

 then move more rapidly, and it is by this method of movement 

 that they seek to escape the sieve. In rising from the bottom to 

 the surface, they assume a more spiral form. 



The tail of the palolo is furnished with a disk, or with the 

 power of forming itself into one. When examining some speci- 

 mens under the microscope, in 1876, I observed one fix itself by 

 a circular disk to the plate upon Avhich T had placed it. It 

 remained fast for some little time. On my touching it, it let go 

 its hold and wriggled about ; but it soon attached itself again, 

 as before. The circular disk was very conspicuous when thus 

 fixed, but was im2)erceptible when the animal was free. This 

 poAver of attachment explains how these Avorraa can remain so 

 long as they generally do concealed among the coral. It may 

 also suggest an explanation of the phenomenon recorded in the 

 ' Samoa Times ' of 16th April, 1881, viz. that, on the previous 

 21st of March, large quantities had appeared on the reef near 

 the village of Gagaemalae, on Savaii — the appearance at such a 

 time, instead of during the month of October, having never 

 before been observed by the oldest inhabitants. The explanation 

 may be this : some unusual local occurrence affecting the reef 

 may have detached the worms from their holding-places, and 

 caused their untimely appearance. 



The worms have never been knoAvn to appear either at the 

 immediate end of September or beginning of October. No doubt 

 they adhere to the coral, in situations in which they cannot be 



