324 MOLLUSCOIDEA— BRYOZOA phylum v 



Family 10. Eleidae d'Orbigny. 



Zoaria ramose^ bifoliate or uni-lamellate. Zooecial tuhes dilating outvjardly, with 

 perforated loalls. Äpertures lateral and siih-terminal^ many of them closed hy ihin 

 calcareous films. Vicarious avicularia and seines scattered among the zooecia in some of 

 the genera. Cretaceous. 



The members of this family difFer widely from the true Cyclostomata, and the presence of 

 avicularia indicates strong affinities with the Chilostomata, The Eleidae undoubtedly 

 represent connecting links between the Cyclostomata and Chilostomata. The simplest type 

 of Eleid structure is found in the Jurassic geniis Haploceeia Gregory, now placed in the 

 Entalophoridae, in which the aperture is subterminal, instead of terminal, and is constricted 

 laterally. 



Reptelea d'Orb. Zoarium adnate, no avicularia. 

 Elea d'Orb. Zoarium erect, bifoliate ; no avicularia. 



Meliceritites Roemer {Inversaria Hagenow ; Escharites Roemer). Cylindrical 

 branching stems ; avicularia present. 



Foricula d'Orb. Like Meliceritites but has walls pierced by pores. 

 Semielea, Nodelea d'Orb. ; Reptoceritites Gregory. 



Suborder B. CANCELLATA Gregory. 



Zooßcia monomorphic with walls perforated hy cancelli, that is, hy roimded or elongate 

 pore-like cavities different from the usual interspaces or mesopores. 



This suborder which is more convenient than natural, developed in early Cretaceous 

 times from certain specialised species of the Idmoneidae. 



Family 11. Horneridae Hincks. 



Zoarium erect and hranched ; zooecial äpertures only on the ohverse side and irregulär 

 or arranged in simple lines. Walls of zoarium traversed hy fine canals luhich appear 

 at the surface as minute pores. Cretaceous to Recent. 



Hornera Lamx. ; Siphodictyum Lonsdale ; Hemicellaria d'Orb. ; Phormopora Marsson. 



Family 12. Petaloporidae Gregory. 



Bamose Cyclostomata with zooßcia opening on all sides of the branches and walls 

 perforated by numerous mural pore structures, somewhat resembling mesopores. 



Petalopora Lonsdale {Gavea d'Orb.) ; Sparsicavea d'Orb. ; Gavaria Hagenow ; 

 Reptocavea d'Orb. Cretaceous and Tertiary. 



Suborder C. DACTYLETHRATA Gregory. 



Cyclostomata with long cylindrical zomcia separated hy dactylethra, that is, by short 

 aborted zocecia closed externally. No cancelli, mesopores or avicularia. 



Family 13. Olausidae d'Orbigny. 



Zoarium adnate or erect with the zocecia distributed uniformly and separated by 

 circles of shallow interstitial cells (dactylethrae) closed at the surface. 



Clausa d'Orb. {Claviclausa d'Orb.). Zoarium erect and dendroid. Cretaceous and 

 Tertiary. 



