JAPANESE PALOLO, CEEATOCEPHALE OSAWAI, N. SP. 35 



As before mentioned, forms transitional to the epitoca appeared 

 at the end of September and became very numerous in the be- 

 ginning of October. After that a sharp look-out for the swarming 

 was of course daily maintianed on the river, at the same time 

 continuing the examination of fresh specimens obtained every 

 other day. In this way, I could approximately foresee the 

 approach of the swarming, quite independently of the forecast 

 made by the fishermen as there suit of the experience of many 

 years. 



After each swarming period the transitional half-epitocous 

 forms, such as are shown in PI. I., tig. 5, totally disappear for 

 a time from among the worms collected from the river-bottom. 

 However, in about ten clays, — that is to say, a few days before 

 the next swarming period, — a plenty of the half-epitocous worms 

 are again met with in the mud ; it is needless to say that these 

 are to take part in the next swarming. After the last swarming 

 at the end of November, there are to be found in the river- 

 bottom only small atocous worms, which probably attain sexual 

 maturity in the autumn of the following year. 



In the years 1898 and 1899, I made only occasional obser- 

 vations on the swarming so that my records for those years are 

 not so complete as for the two preceding years. Nevertheless, it 

 can be confidently stated that the swarming in the years mentioned 

 took place quite in accordance with our previous observations, — 

 that is to say, it occurred at periods and hours, which could be 

 foretold. The number of swarming worms was variable as before, 

 and sometimes very small. 



To give in general terms the results derived from my 

 observations : 



