THE GRAPTOLITES AND CORALS 3'3 



SUB-ORDER: Fungida. Dissepiments replaced by cal- 

 careous rods (synapticiilce) crossing the interseptal loculi. 

 Genera : Anabacia (Jur.), simple, discoidal ; Cyclolites 

 (Jur.-Eoc.), similar, but septa are thin and perforate, thus 

 approaching the next sub-order ; Thamnastraa (Jur.), 

 compound, massive, septa continuous from one corallite 

 to its neighbours. 



SUB-ORDER: Perforata. All parts of the skeleton 

 traversed by pores, which may reduce it to a spongy 

 network. Genera : Stephanophyllia (Cret.-Rec.), simple, 

 discoidal; Dendrophyllia (Eoc.-Rec.), compound, tree-like 

 (dendroid); Goniopora [Litharced] (Eoc.-Mio.), compound, 

 massive. 



SUB-CLASS : Alcyonaria. Skeletons of very variable 

 character. Many extinct forms are doubtfully placed 

 here. Septa usually feeble or absent, and never showing 

 either a tetracorallan or hexacorallan plan ; tabulae 

 well developed. All compound. Genera : Favosites 

 (Sil.-Carb., Fig. 94, k), massive, corallites polygonal, 

 septa vestigial, tabulae horizontal and regularly spaced, 



FIG. 94. FOSSIL CORALS. 



a, Palceocyclus porpita (Linne"), Wenlock Limestone. Plan of calyx, 

 detail omitted from three quadrants, a', Side view. (Xl-) b, Lons- 

 daleiajloriformis (Fleming), Visean (Carboniferous Limestone). Cross- 

 section of single corallite. (Xa.) b', Side of young corallum. (Xj.) 

 c, Cyathophyllum hexagonum Goldfuss, Middle Devonian. Cross- 

 section of single corallite. ( x g.) Dissepiments omitted from greater 

 part. d. Calceola sandalina Lamarck, Middle Devonian. (Xj.) 

 d', Operculum. (After Goldfuss.) e, Thecosmilia annularis (Fleming), 

 Argovian (Coral Rag). (Xj.) /, Isastrcea oblonga (Fleming), Port- 

 landian Section of silicified corallum. (X3-) Thecas and septa 

 white, g, Holocystis elegans (Fitton), Aptian (Atherfield Clay). 

 Surface of part of corallum. (X6.) Septa and columella, black; 

 theca, dotted. A, Heliolites porosa (Goldfuss), Middle Devonian. 

 Transverse section. (Xl-) i, Halysites catenularia (Linne"), Silurian. 

 Diagrammatic view of portion of a corallum. (Xf.) /, Syringopora 

 ramvlosa Goldfuss, Lower Carboniferous. (Natural size.) k, Favo- 

 sites gothlandica Lamarck, Wenlock Limestone. Diagrammatic view 

 of four corallites. (X4-) The exterior of three is seen, with mural 

 pores, the fourth is split vertically in half, showing tabulae, d, After 

 Goldfuss ; i and k, original ; the rest after Edwards and Haime, 



