OF 8ERTULARIAN ZOOPHYTES. 179 



probably by the polype being renewed at intervals, and each 

 fresh polype forming a new cell within the old one. 



I have met with what appears to be the young of this species, 

 parasitical on Tubularia indivisa and Sertularia ahietina. In this 

 state it is remarkably delicate and beautiful, and might be taken 

 for a distinct species. The stems rise from a creeping fibre, and 

 are very strongly and profusely ringed; they give off branches 

 from the base of each cell, and sometimes two from one cell. 



A specimen of the adult form, without capsules, has been sent 

 me by Mr. Macdonald of Elgin, obtained in the Moray Frith ; and 

 Mr. Barlee has also met with it lately in Shetland. 



Plate XIa. 



Figs. 1 & 2. Plumularla halecioldes, naturtil size and magnified. 



Fig. 3. A portion more higlily magailied. 



Fig. 4. Ovicapsules. 



Fig. 5. A portion of the compound stem. 



Plate XII. 



Fig. 1. Halecium labrosum^ natural size. 

 Fig. 2. A portion magnified: «, capsules. 

 Fig. 3. A portion of a variet^^ magnified. 



