44 COMPARATIVE ANATOMY AND PHYSIOLOGY. 



in the sea-pen (Pennatula) (Fig. 1 4 B), the tissue which 

 connects the polyps together is horny, in the noble red 



Fig. 14 c. Gorgonia fldbellum. 



coral it is calcined, while in the sea-fans (Gorgonia) an 

 elegant hard network is developed (Fig. 14 c). 



II. The HexactmisB ; the six tentacles or mul- 

 tiples of that number are filiform, and their edges 

 smooth. Some, like the common sea-anemone, 

 remain single throughout life, but, in most, buds are 

 given, otf, and a colony is formed. The deposition of 



