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COLLEGE ZOOLOGY 



This order includes the sea-fans which are to be found in 

 almost every museum, and the precious red coral {Cor allium, 

 Fig. 89, C), which occurs in the Mediterranean and is widely 

 used in the manufacture of jewelry. 



Order 4. Pennatulacea. — Alcyonaria forming bilaterally 

 symmetrical colonies; zooids usually borne on branches of an 



Fig. 8g. — Coral. A, Tubipora musica, organ-pipe coral, a young colony. 

 Bp, connecting horizontal platforms; p, skeletal tubes of the zooids; St, 

 the basal stolon. B, Alcyonium digitatum, with some zooids expanded. C, 

 Corallium, a branch of precious coral. P, polyp. D, Pennatula sulcata, a sea- 

 feather. (A and B, from Cambridge Natural History; C, from Sedgwick, after 

 Lacaze Duthiers; D, from Sedgwick, after Kolliker.) 



axial stem, which is supported by a calcareous or horny skeleton. 

 Examples: Pennatula (Fig. S9, D), Rcnilla. The sea-pens 

 (Fig. 89, D) live with their stalks embedded in muddy or sandy 

 sea-bottoms. Many of them are phosphorescent. 



