Zoology.] NATURAL HISTORY OF VICTORIA. \_Polyzoa. 



indistinct. This divides usually into two, which again subdivide 

 into several branches. From the main branches others spread on 

 either side in a penniform manner, and these again give rise to 

 smaller branches. These anastomose irregularly together, and the 

 large branches from the neighbouring main stems frequently unite 

 in the same manner. Some specimens consist only of a single 

 stem with lateral branches. The resulting zoarium in those with 

 several stems is more or less expanded and curled. The anastomoses 

 are very irregular, and do not produce anything like the regular 

 fenestrate arrangement seen in Retihornera foliacea. They seem 

 to be frequently caused by the accidental contact of the peristomes 

 of zocecia in contiguous branches. 



Explanation of Figures. 



Plate 118. — Fig. 6, specimen, natural size. Fig. 7, portion of a specimen, showing the 

 anterior surface and the mode of formation of the anastomoses, magnified. Fig. 8, small portion 

 of the back of another specimen, showing an ocecium. 



Mr. MacGillivray has kindly contributed the specimens and 

 descriptions of these species of Retihornera and Hornera. 



Frederick McCoy. 



[73] 



