34 BE. J. W. GEEGOEY ON THE GEOLOGY AND [Feb. IQOO, 



C. similis, M.-Ed. & H. 1 has corallites of a similar size, but 

 Las the septa less numerous and well developed than those of 

 C. PhiUijpsice. 



3. COLUMNASTEJEA MAXIMA, Sp. nOV. 



Diagnosis. — Corallum nodular; comparatively small. 



Corallites very large ; fused together by thick walls, which, in 

 weathered specimens, stand out above the level of the corallum, 

 separating the depressed calices. 



Septa in three orders. 



Dimensions. — Diameter of corallites = 10 to 12 mm.; distance 

 of ealicinal centres = 12 to 13 mm. 



Distribution. — Uradu Limestone: Uradu. Coll. Mrs. Lort 

 Phillips. 



Genus Peionaste^a, Milne-Edwards & Haime, 1848. 



Petonaste^a ceassisepta., sp. nov. (PI. I, figs, o a, 5 b, & 6.) 



Diagnosis. — Corallum in rounded masses; heavily calcified. 

 The corallites are large, polygonal, closely crowded, and intimately 

 united throughout by their walls. 



Calices comparatively shallow. 



i^epta in four complete cycles ; the primary and secondary septa 

 are very thick, and reach the columella. 



Columella broad, but not very conspicuous ; it is about one-fifth 

 of the diameter of the corallite, and composed of very spongy tissue. 



Dissepiments abundant. 



Dimension s. — Diameter of corallum = 90 by 70 mm. ; of average 

 corallite = 20 mm. ; of columella of the same = 4 mm. 



Distribution. — Dobar Limestone: Dobar, south of Berbera. 

 Coll. Mrs. Lort Phillips. 



Affinities. — This coral resembles Dimorphoccvnia crassi septa, 

 de From. 2 by the great thickness of its septa ; but it differs by the 

 presence of the columella, the absence of the concentric arrangement 

 of the corallites, and other characters. The septa are thicker than 

 in any other known species of Prionastrcea, of which it is the 

 earliest representative. The previous records of the genus from 

 the Jurassic are based on species of Isastrcea. 



Genus Cceloria, Milne-Edwards & Haime, 1848. 

 1. Coeloeia aeabica, Klunzinger. 



1879. Cceloria arabica, Klunzinger, ' Korallth. roth. Meer.' pt. iii, p. 17 & pi. ii, 

 fig*. 1, 3, 8 ; pi. ix, fig. 10. 



Distribution. — Raised reefs. In the Guban, near Berbera. 

 Coll. Capt. E. T. Marshall. Two small fragments. 



1 Milne-Edwards & Haime, ' Monogr. des Astreicles ' Ann. Sci. Nat. ser. 3, 

 vol. xii (1849) p. 184. 



2 E. de Fromentel, ' Deser. Polyp, foss. Etage Neocom.' (1857) p. 55 & pi. viii, 

 fig. 1. 



