566 POLYZOA. 



circular aperture, the lower margin entire, and a semilunate or circular pore 

 below it. Microporella H. ; Dipomla H. ; Cliorizopora H. ; Flustramorpha Gray. 



Fam. 19. Porinidae. Zoarium encrusting, or erect and ramified. Zooecia 

 with a raised tubular or subtubular orifice, and frequently a special pore on the 

 front wall. Porina d'Orb. (Tessaradoma Norman) ; Anarthropora Smitt ; 

 Lagcnipora Hincks ; Celleporella Gray. 



Fam. 20. Myriozoidae. Zoarium encrusting, or rising into foliaceous 

 expansions, or dendroid. Zooecia calcareous, destitute of membranous area 

 and of raised margins ; orifice with a sinus on the lower lip. Schizoporella H. ; 

 Mastigophora H. ; Rhynchozoon H. ; Hippothoa Lamx. ; Myriozoum Donati ; 

 (Gephyrophora B. ; Haswellia B. ; Gemellipora Smitt). 



Fam. 21. Escharidae. Zoarium calcareous, encrusting, or erect and lamellate, 

 or ramose. Zooecia without a membranous area or raised margins. "Without 

 special pores and orifice without a true sinus. Lepralia Johnston ; Umbonula 

 H. ; Porella Gray ; Escliaroides Smitt ; Smittia H. ; Phyladella H. ; Mucronella 

 H. ; Palmicellaria Alder ; Eschara Pallas ; Aspidostoma H. 



Fam. 22. Adeonidae. Adeona Lamx. ; Adeonella, B. ; Reptadeonella B. 



Fam. 23. Celleporidae. Zooecia calcareous, more or less vertical to the 

 plane of the colony, irregularly heaped together, with a terminal orifice. 

 Cellepora Fabricius. 



Fam. 24. Selenariidae. Cupularia and Lunularia Lamx. ; Selenaria Busk. 



Sub-order 2. CYCLOSTOMATA. 



Zooecia tubular, with a plain terminal orifice without operculum. Without 

 movable appendages. The ovicells are modified zooecia. Many fossil species. 



Tribe A. ARTICULATA. With erect branches divided at intervals by 

 chitinous joints. 



Fam. 1. Crisiidae. Zoarium dendroid, calcareous, composed of segments 

 united by corneous joints. Crisia Lamx. 



Tribe B. INARTICULATA. With unjointed zoarium. 



Fam. 2. Tubuliporidae. Zoarium entirely adherent, or more or less free and 

 erect, multiform, often linear, or flabellate or lobate, sometimes cylindrical. 

 Zooecia tubular, disposed in contiguous series, or in single lines. Ooecium formed 

 by the inflation of the branch. Aledo Lamx. ; Tubulipora Lamx. ; Stomatopora 

 Bronn ; Jdmonea Lamx. ; Entalopliora Lamx. ; Diastopora Lamx. ; Pustulopora 

 Blainv. 



Fam. 3. Horneridae. Zooecia opening on one side only of a ramose zoarium, 

 never adnate and repent. Horncra Lamx. 



Fam. 4. Lichenoporidae. Zoarium discoid, simple or composite, adnate, or 

 partially free and stipitate. Zooecia tubular, erect or suberect, disposed in more 

 or less distinct series, which radiate from a free central area ; the intermediate 

 surface cancellated or porous. Lichenopora Defrance ; Domopora d'Orb. 



Fam. 5. Frondiporidae. Frondipora Imperato ; Fasdculipora d'Orb. ; Super- 

 cytis d'Orb. 



Sub-order 3. CTENOSTOMATA. 



When the tentacle-sheath is retracted, the orifice of the zooecium is closed 

 by a folded membrane as by an operculum. Zoarium never calcareous. Ovicells 

 and appendages absent. 



