Plate XXXI. 



Fig. 116. Sertularella tenella. 



A. Natural size. 



B. Portion of stem showing hydrothecee. 



C. Gonangium (After Hincks). 



Fig. 117. Sertvlarella tricuspidata. 



A. Natural size. 



B. Portion of stem showing branching and hyd othecse. 



C. Much elongated hydrothecae. 



D. Gonangium. 



Fig. 118. Sertularella turgida. 



A. Natural size. 



B. Portion of stem showing hydrothecaî and gonangia. 



Fig. 119. Sertularia jurcata. 



A. Natural size. 



B. C. Portions of stem showing difference in front and back. 

 D. E. Gonangia. 



