ORDER V 



CHEILOSTOMATA 



353 



semicircular to sub-orlncular, the loAver margin witli a distiiict siniis. Cretaceoiis to 

 Recent. 



Family 14. Meniscoporidae Caiiu. 



This family is characterised by the occurrence of three kinds of zooecia : (1) 

 typical zocecia, (2) genesies or zooscia bearing internal oa3cia, and (3) aviciilaria. 

 Abundant in Tertiary. 



Meniscopora Gregory. Aperture constricted as in Hippoporina. 



Schizostoma Canu. Like Schizoporella biit with genesies. 



Poristoma, Poricella, Smittistoma and Galvetina Canii ; Lohopora Levinsen. 



Family 15. Reteporidae Smitt. 



Retepora Imperato {Phidolophora Gabb and Hörn) (Fig. 523). Zoaria consisting 

 usually of inosculating brancbes whicb spring from an encrusting base. Zooecia 

 disposed on one face of tlie brancbes only, in most cases immersed. Primary orifice 



Retepora celhdosa Linn. Cra^ 

 Suffolk, England. 



Fig. 524. 



Myriozoum jninctatum (Phill.). Miocene ; Ortenburg, Bavaria. A, 

 Zoarium, i/i- B, Upper surface, enlarged. In the forward portion the 

 apertures are open ; in the rear, covered over by a calcareous deposit. 

 C, Gross section of a branch. 



rounded or semi-elliptical with entire border. Afterwards the peristome becomes 

 miicli raised and multiform ; usually there is a fissure below, or there may be a 

 prominent rostrum bearing an avicularium. Tertiary and Recent. 



Family 16. Myriozoidae Smitt. 



Myriozoum Donati {Myriopora Blainv. ; Vaginopora Reuss) (Fig. 524). Zoaria 

 consisting of thick, dichotomously dividing branches, obtuse at their growing ex- 

 tremities, and rising from an attached basal expansion. Zooecia disposed about an 

 imaginary axis, even at the surface, their boundaries scarcely distinguishable. Entire 

 surface and also the inner walls minutely porous. Orifice above the centre of the 

 zooecium, sub-orbicular, notched or canaliculate below. As a rule, the openings are 

 closed on the lower parts of tlie branches by a calcareous pellicle. Tertiary and 

 Recent ; perhaps also Cretaceous. 



Family 17. Celleporidae Busk. 



Zocecia urceolate, more or less erect, and irregularly crowded together ; often forming 

 several or many superimposed layers. 



Gellepora Fabricius, emend. Busk (Spongites Oken ; Celleporaria Lnmx.) (Fig. 

 525). Zoarium multiform, encrusting, or erect and ramose. Zocucia in the oldcr 

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