OS'2 1. IKEJDA : 



tliemselves to the tiil)es of tlu' already Ibnned colonies, liourisli aiul 

 attain fall growth ; on the other hand, if the larvae become 

 attached at some nnfavorable places, they mnst soon l)e washed (Aï 

 by waves and many of them must 2)ei'ish before they can find other 

 suitable places. To this wasteful death of the larvte which have 

 lost the o])portunity of iindini;' suital)]e localities to grow on, must 

 be due the fact that they remain comjjaratively stationary in the 

 nundjer of colonies and in their distriltution. 



Specific Position of Phoronh Ijimal (Jka. .Vccording to 

 CoRi's table, there are 7 known s])ecies of Phoronis. But I can 

 uöt refrain fi'oni entertaining serious doul)ts as to the correctness of 

 the present mode of classifying the Phoi'onidœ in general. i\Iost of 

 the systematic data have hitherto been taken from the external 

 characters of the animals, such, for instance, as the colour and si/e 

 of the body, the number of tentacles, the general foi'm of the 

 colony, etc. The question now is whether these external characters 

 are constant and can be de])ended upon for systematic use. Is 

 there not a necessity for taking internal anatomical points into our 

 consideration? ^Vccording to my (jbservatiojis, P/ioro/us ajuuially 

 chanues its ireneration and al)out one half of the vear belongs to 

 the growing ])eriod. Specimens collected during this growing 

 season must necessarily differ from the adult in the breeding season 

 in the mmd)er of tentacles, in the length and size of the body, 

 etc. Wide disci'epancies are therefore found between ( )ka's obser- 

 vation and mine on the same s])ecies, riz., Plioroni^^ ijiiitai. I 

 have no doubt that Oka made use of oidy the younger indivi- 

 duals as will be obvious from the following comparison : 



Biidy length. XuihIrt hI' tentacles. Lengtli of teiitaeles. 



Oka 40 mm. 1.30 (aver.) 2 imn. 



Ikeda ^-IÇiQ) mm. 200-210 (aver.) bmm. 



