1 68 



MANUAL OF ZOOLOGY. 



proximal end is smooth and fleshy, and is probably sunk in 

 the mud of the sea-bottom. This latter portion of the cceno- 

 sarc is likewise strengthened by a long, slender, styliform 

 sclerobasis, resembling a rod in shape, whilst spicula occur 

 also in the tentacles and ectoderm. The general colour of 

 Pennatula is a deep reddish purple, the proximal extremity 

 of the coenosarc being orange-yellow. The common British 

 species (Pennatula phosphorea) varies from two to four inches 

 in length, and is found on muddy bottoms in tolerably deep 

 water. Its specific name is derived from the fact that it phos- 

 phoresces brilliantly when irritated. 



In Virgularia (fig. 82), which, like Pennatula, occurs not 

 uncommonly in British seas, the actinosoma is much longer 

 and more slender than in the preceding, and the polype-bear- 

 ing fringes are short. The polypes have eight tentacles. The 

 sclerobasis is in the form of a long calcareous rod, like a knit- 



Fig. 81. Colony of Veretillum cyno- 

 morium, of the natural size, with the 

 polypes protruded. 



Fig. 82. Pennatulidae. 

 Virgularia mirabilis. 

 a A portion of the stem 

 in the living condition, 

 enlarged ; b Portion of 

 the stem in its dead 

 condition. 



ting-needle, and part of it is usually naked. No spicula are 

 found in the tissues of Virgularia. In the nearly-allied Pavon- 

 aria the polype-mass is quadrangular in shape. 



In Veretillum (fig. 81), the upper portion of the colony is 

 short and club-shaped, and carries the polypes all round its 

 circumference, and the same is the case in Cophobelemnon ; 



