FRENCH GONIOPOR^. 



133 



the other in that of the Abbe Leveque at Vaugirard. An unattached corallum, a flattened 

 cpitheca, and the closing up of interseptal loculi by synapticulse are all indications of a sandy 

 or muddy substratum, see p. 75. 



125. Goniopora Paris Basin (i4)2. (PI. IX. fig. 7 ; PI. X. fig. 1.) 



[Parnes and Valmondois, encrusting Campanik gigcmteum, (Middle Eocene, Calcaire Grossier) ; 



ISritish Museum.] 



Astrwa bellula, Michelin, Icones (1844), p. 158, pi. xhv. fig. 2. 



Description. — Corallum very thin, encrusting, following the irregularities of the surface, 

 \vith sharp edges sloping very gradually down to the substratum. 



Calicles from 2 to 2 ■ 5 mm. across, polygonal, regular near the centre, but irregular, being 

 drawn out lengthways, round the growing edges. The walls thin, sharp, very pronounced 

 though not very high, the depression being a smooth shallow convex. The wall-thi-ead is 

 irregular, here and there thickened, but never regularly beaded like the septa. To the naked 

 eye there appear to Ije about 15 to 16 rough, wedge-shaped, very perforate septa, very thick 

 near the walls but tapering away towards the centre. The roughness is due to their edges 

 being moniliform and consisting of close rows of small beads. Many of the thicker septa 

 are really double near the walls, the rows of beads forking. No approach to the typical 

 septal formula can be made out, however, owing partly to the distortion of the calicles. The 

 septa are always straight, and when they fuse do so at sharp angles. 



The septa meet irregularly to form a tangle, sometimes large, sometimes small, and the 

 rows of bead-like granules along the edges of the septa run on to this tangle, so that it appears 

 iinely papillate. 



Of this beautiful Goniopora there are fortunately in the Museum Collection two small 

 encrusting patches upon a specimen of Campanile giganteum (PI. IX. fig. 7). The beads 

 along the edges of the septa appear closely set and rounded, under the lens they are rougher 

 and somewhat angular. Kouud the edges and even elsewhere the calicles are quite excentric, 

 those at the very margin sending out long septa upon the epithecal film. 



The coral described by Milne-Edwards and Haime as Litharma bellula can hardly have 

 been the same as this (see next heading). Milne-Edwards' coral was said to have been 

 convex, while this coral is but very slightly so. The walls of this coral are not what I should 

 call " peu marquees," nor should I describe the septal formula as " deux cycles complets, et 

 des cloisons tertiaires dans deux des systemes," with septa "uu peu epaisses"; nor is there any 

 indication on the Museum specimens, nor iu ^Michelin's figure, of the innermost of the septal 

 beads being larger than the rest and simulating pali. Further, Milne-Edwards says nothing in 

 'Les Coralliaires' of the moniliform septa, nor of the coral being attached to the shell of 

 C'ampa7iile. The septa of his coral were " legerement flexueuses et faiblement granulees." 



The two specimens are close to one another, and one has large calicles. In both the edges 

 of the septa are beaded. Such beading may be a post-mortem (corrosion) modification of 

 sharper, crisper points, but in this case the vertical section shows that the trabecule were 

 short and thick, and that the beads are their unaltered tips. 



«• Geol. Dept. E. 4816. 



