1 32 MADREPORARIA. 



123. Goniopora Gironde (2) 2. (PI. IX. fig. 6 f PI. XIV. fig. 7.) 

 [Peloua, near Bordeaux, Gironde (Lower Miocene, Burdigalian) ; British Museum. ] 



Description. — Corallum massive, growth-form unknown. 



Calicles average about 5 mm. across, with a few larger up to 7 mm., buds of all sizes 

 between. Walls of nearly regular thickness, over 1 mm., of stout very flaky reticulum, not 

 unlike the interstitial tissue of a Favia, except that the walls are perforate. Septa in the adult 

 calicles have the typical formula ; a few additional septa appear in the very large calicles 

 obscuring the arrangement. The septa are laminate, and only slightly perforate, not so wavy 

 as to prevent the radial symmetry from being conspicuous. The tertiaries may end freely 

 or else bend round sharply to fuse with the secondaries about half-way between the wall 

 and the columellar tangle, which is a coarse, open, and quite irregular reticulum. 



Numerous tabula?, frequently arranged so as to show that the floor of the calicle cavity 

 •was convex. They are so strongly marked as to remind one of the vesicular tissue of many 

 Palaeozoic corals. 



There is only one beautifully preserved specimen, which has been rolled like a pebble. 

 That the large exposed calicles are not those of the original surface may be gathered from the 

 traces of tabula? seen in them. In this display of tabula? by wearing down of the surface, 

 cf. 6. Paris Basin 10, PI. X°. figs. 1 and 2. For large calicles see G. Dax 2 ; but in that 

 coral there is a crowding of the septa near the wall which is not the case here, cf. PI. IX. 

 figs. 4 and 6. 



a. Geol. Dept. R. 2203. 



124. Goniopora Paris Basin (1 4)1. 



[Cuise-La-Motte, Compiegne, Oise (Lower Eocene).] 



Litharcea gravesi, Milne-Edwards and Haime, Polyp. Foss. des Terrains Pal. (1851), p. 143. 

 Astrcea crispa, Michelin, Icones (1840-47), p. 162, pi. xliv. figs. 7 a, b. 



Description. — Corallum hemispherical, free (with flattened epitheca). 



Calicles polygonal, 3-4 mm., and slightly funnel-shaped ; walls somewhat prominent, 

 with thin, rather straight edges ; septa in three complete cycles, extremely thin, " armed with 

 •conspicuous conical points." The two first cycles equal in length ; the tertiaries fuse with the 

 secondaries half-way along their courses. The columellar tangle moderately developed. 



This was evidently one of the typical Paris Basin Gonioporm, belonging to the group * in 

 which the septa are beset with lateral synapticular projections, sometimes indeed showing a 

 high degree of development, G. Paris Basin 5, 6 and 7. Michelin's figure shows very slight 

 indications of these synapticular points, hardly justifying the expression " tres saillants." 



The walls were thin and sharp like those of the next coral, and the growth-form was 

 primitive. Michelin says that he only knew of two specimens, one in his own collection and 



* On the morphological grouping of the Paris Basin forms, see the Remarks p. 145. 



