144 



THE ANATOMY OF INVERTEBRATED ANIMALS. 



Fig. SO.— Coralli'im rubrum (after Lacaze-Dnthiers i). 



I. The end of a bruiich with A, B, C, three anthozoQids in different desrees of ex- 

 pansion ; k\ tlie month ; a, that part of the ccenosarc which rises into a cup 

 around the hase of each antliozoSid. 



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

 partially removed ; B, B^, B'\ anthozoSids in section ; B. anthozooid with es- 

 pa\ided tentacles; ^, mouth ; m, gastric sac ; i, its inferior edge; 7, mesenteries. 



B\ anthozoOid retracted, with the tentacles {d) drawn back into tlie intermesenteric 

 chanil)er-!; c. orilices of the cavities of the invaainatcd tentacles ; ^. circum-oral 

 cavity ; b, the part of the body which forms tlie projecting tube wlien the antho- 

 zooid is expanded : a. festooned edges of the cup. 



B'\ anthozooid, showing the transverse sections of the mesenteries. 



A^ A. ccenosarc, with its deep longitndinal canals (./ ), and superficial, irregular, 

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

 {g) answerinc: to the longitudinal vessels. 



III., IV. Free ciliated embryos. 



1 " Ilistoire Nuturelle du Corail," 1864. 



