144 THE ANATOMY OF INVERTEBRATED ANIMALS. 



FIG. 3Q.Oora!lium rubrum (after Lacaze-Duthiers J ). 



I. The eud of a branch with A, 5. C, three anthozoOids in different degrees of ex- 

 pansion ; k, the mouth ; a, that part of the ccenosarc which rises into a cup 

 around the base of each anthozoOid. 



II. Portion of a branch, the coenosarc of which has been divided longitudinally and 

 partially removed; B, B f , B', anthozoOids in section; B, anthozoOid with ex- 

 panded tentacles; k. mouth ; m, gastric sac; z, its inferior edge; ,/, mesenteries. 



B', anthozoOid retracted, with the tentacle? (d) drawn back into the intermesenteric 

 chambers; c, orifices of the cavities of the invaginated tentacles ; e, circum-oral 

 cavity ; 6, the part of the body which forms the projecting tube when the antho- 

 zo3id is expanded : a, festooned edges of the cup. 



B", antiiozoOid, showing the transverse sections of the mesenteries. 



-4, A, ccenosarc, with its deep longitudinal canals (/), and superficial, irregular, 

 reticulated canals (h). P, the hard axis of the coral, with longitudinal grooves 

 (g) answering to the longitudinal vessels. 



III., IV. Free ciliated embryos. 



i " Histoire Naturelle <Ju Corail," 1^64. 



