Fig. 4

(Scale bar = 10 mm, unless otherwise stated): a Stylophora wellsi Scheer 1964, Ad 25-a 7, Samadai Formation, Wadi Abu Dabbab; a1 entire corallum with short, knobby branches; a2 close up view showing the calices with their internal elements; two orders of septa and the styliform columellae. b Pseudosiderastrea tayamai Yabe & Sugiyama 1935, Sh.L 7-b 5, Pleistocene raised reefs (T I), Sharm El-Luli; b1 a large massive corallum with cerioid corallites; b2 close-up view on the cerioid corallites showing the septal arrangement and fusion; b3 transverse thin section, showing a single corallite with septothecal wall and occasional thin synapticulothecal elements. The box is the area shown in Fig. b4; b4 enlarged part of the area enclosed in the box shown in Fig. b3, showing septothecal wall with occasional synapticulothecal elements (arrows) c Psammocora haimeana Milne-Edwards & Haime 1851, Sh.F 3-b 19, Samadai formation, Wadi Sharm El-Fuquiri; c1 massive rounded corallum; c2 close-up view showing the corallites are separated by well-defined synapticulothecal walls d Favites chinensis (Verrill 1866), Ad 26-6, Pleistocene raised reefs, (T I), Wadi Abu Dabbab; d1 massive corallum with angular cerioid corallites; d2 close-up view of the area enclosed in the black box in Fig. d1, showing the cerioid corallites with intratentacular budding and endothecal dissepiments fill the calices in the form of concentric rows between the septa