ORDER II 



CYCLOSTOMATA 



321 



arranged in regulär, spiral or transverse linear series, and closely situated. Zooecial 

 tubes disposed about a definite central axis or axial tube. Jurassic to Kecent. 



Diploclema Ulr, Similar to Entalophora, but witli branches spreading in the 

 same plane, slightly conipressed, and divided into two equal parts by a wavy mesial 

 lamina, Silurian. 



Haplooßcia Gregory. Like Spiropora, but distal ends of zooccia are angular. 

 Jurassic and Cretaceous. 



Mitoclema Ulrich. Ordovician. Clonopora Hall. Devonian. Peripora d'Orb. 

 Cretaceous. 



Rhipidopora and Glinopora Marsson ; Siphoniotyphlus Lonsdale ; Clypeina Michelin ; 

 Umhrellina Roemer. Cretaceous and Tertiary. 



Family 5. Fasciporidae d'Orbiguy (emend.). 



Zooßcia tubulär^ opening in Clusters at the 

 (jrowing extremities^ and in linear or quincuncial 

 series on the sides of the lamelliform, or ohconical 

 zoaria. Äccessory pores wanting. Cretaceous. 



Fascipora d'Orl». (Fasciporina d'Orb.). Zoaria 

 conipressed, sub-rainose to lanielliforni. Aper- 

 tures arranged quincuncially or somewliat ir- 

 regularly on both sides, and on the more or less 

 expanded growing extremities of the branches 

 and laniellae. The lanielliform species resemble 

 Diastopora, but are without a mesial lamina. 



Semifascipora d'Orb. (Fig. 446). Zoaria cup 

 or funnel-shaped, with only the outer surface 

 poriferous, the inner covered by an epitheca. 

 Poriferous face thrown into vertical ridges 

 bearing the salient tubulär mouths of one or 

 more rows of zooecia. At the upper edge the ridges pass into large Clusters of apertures. 



Conotuhigera and Serietuhigera d'Orb. Closely related to the preceding. 



Fia. 446. 



Semifasci'pora variabilis d'Orb. Cretaceous ; 

 France. Side view of zoarium, lO/j. 



Fig. 447. 



Fascirulijwra incrassata d'Orb. Upper 

 ('retaceous ; Meudon, near Pari.s. Terminal 

 tVagnient, mt. size and enlarged (after 

 d'Orbigny). 



Family 6. Fascigeridae d'Orbigny. 



Zoarium composed of bundles of long, parallel 

 zooecia free for most of their length, with the aper- 

 tures in groups at the ends of the bundles. 



Fasciculipora d'Orb. (Fig. 447). Zoarium of 

 long, simple or divided branches. Jurassic to 

 Tertiary. 



Corymbopora Michelin. Like Fasciculipora 

 but sides of branches marked by numerous pores. 

 Cretaceous. 



Apsendesia Lamx. Zooecial bundles arise from 

 a small cup-shaped disk. Jurassic and Cretaceous. 



Discofascigera d'Orb. Cretaceous and Ter- 

 tiary. 



Family 7. Theonoidae Busk. 



Zoarium adnate or erect ; zooecia simple, short, open tubes with apertures confined to 

 crowded bands along raised ridges or on the edge of the fronds. 



VOL. I Y 



