ORDER V 



CHEILOSTOMATA 



349 



tlie Segments sul)-cylindrical and coinicctcd l)y (Icxilde, lioiny tiil)c<. Z^dvia 

 inimerscd, siiii-omidcd hy a laiscd Ix.fder, di.^po^c'd in (juincLinx. 



Aviciilaiia iriegu- 

 larly distiilnited, 

 sitiiated above a cell, 

 or occiipying tlie 

 place of one. 



Fio. 509. 



Cellularia rhombiferu 

 (Goldfuss). Oligocene ; 

 Kanfiingen, near Cassel. 

 Enlarged (after Reuss). 



Encnisting zoarium of Memtranipora, with 

 non-calcifled zocecial walls. Magnified. 



Fig. 511. 



Memhranipora plebeia 

 (G. and H.). Cretaceous ; 

 N. J. Several cells highly 

 magnified (after Gabb and 

 Hörn). 



Family 5. Membraniporidae Busk. 



Zoarium calcareous or membrano-calcareous, encrusting or erect, in the latter case 

 bifoUate, or suh-cylindrical. Zocecia placed side hy side, and forming an irregulär 

 continuous exjpansion, or in linear series. Margins raised, the depressed front more or 

 less memhranous. 



Memhranipora Blainv. (? Marginaria Roemer ; (?) Dermatopora Hagw.) (Figs. 

 510-511). Zoaria encrusting, calcareous or sub-calcareous. Zooecia arranged 

 irregularly or in rows, without a calcareous lamina on the front, or only partially 

 covered by one, leaving a variously sliaped aperture. Jurassic to Recent. 



Tremopora Ortmann. Like Memhranipora, but has a large avicularium and 

 bifurcated spine on tlie border. Tertiary to Recent. 



Hagenoiüinella Canu. Cretaceous. 



Family 6. Selenariidae Busk. 



Zoaria circular or irregulär in outline^ the celluliferous side convex, the lower concave 

 or ßat, prohahly free in the mature condition. Upper surface areolated, the zooecia 



Fig. 512. 



ll;i-w. 



l'l'l' 



CrctacH'ous 

 I', ciilargt'd. 



Ijünt'lutru;. 



