COLLECTED ON THE ' CHALLENGER ' EXPEDITION. 343 



Char. Zoarium multiform, lamellar and incrusting and par- 

 tially adnate, or free ; or erect and attached by a thick base ; 

 massive or irregularly branched, solid or hollow ; or in the shape 

 of small parasitic, pisiform or discoid growths. Zocecia, in the 

 older portions, more or less erect or vertical, very irregularly 

 disposed and heaped together. Orifice entire, or sinuated in 

 front, with one or more small avicularia closely contiguous to it. 

 Often a preoral rostral process (sometimes aborted), usually 

 supporting an avicularium ; very generally interspersed avi- 

 cularia. 



The species of Cellepora here enumerated may be artificially 

 arranged into groups, characterized respectively by the form of 

 the orifice, or, more accurately perhaps, by that of the oral valve 

 or operculum ; whilst a secondary division may be made from the 

 characters afforded by the general zoarial habit f, which may be 

 either incrusting or lamellar, or more or less solid, massive, 

 branched, or lobate. 



§ I. Border of the primary orifice entire ; not sinuated or notched 

 in front (Holostomatous). 



1. C. hastigera. 



2. C. apiculata. 



3. C. nodulosa. 



4. C. zamboangensis. 



5. C. albirostris. 



6. C. tridenticulata. 



§ II. Orifice notched or sinuated in front (Schizostomatous). 

 a. Incrusting or massive, branched or lobate. 



1. C. Simonensis. 6*. C. polymorpha. 



2. C. pustulata. 7- C. tuberculata. 



3. C. cylindriformis. 8*. C. vagans. 



4. C. Eatonensis. 9. C. Jacksoniensis 



7. 



C. columnaris. 



8. 



C. honolulensis 



9. 



C. imbellis. 



10*. 



C. rudis.J 



11. 



C. solida. 



5*. C. ovalis. 



/3. Parasitic, usually pisiform. 



10. C. bicornis. 14. C. ansata. 



11. C. bilabiata. 15. C. canaliculata. 



12. C. signata. 16. C. bidenticulata. 



13. C. conica. 



t Vide Hincks, Brit. Mar. Polyzoa, vol. i. p. 398 et seq. 

 I In the species marked with an asterisk the form of the orifice does not 

 accord with that of the operculum. 



