130 MADREPORAPJA. 



angles. The primaries and secondaries short because they so soon join the columenar laiiule ; 

 very unevenly perforated, here nearly laminate, there very porous. The columellar tangle 

 very large and flaky. Interseptal loculi large and rounded. In the vertical section the 

 lattice-worlc of the vertical trabeculse and the horizontal synapticulai very regular and with 

 large open meshes. An immense number of very delicate tabulas or dissepiments. 



The single specimen is lialf of a worn pebble-shaped fossil. The original surface is gone, 

 and no clue is given as to the character of the walls at the surface. It is a typical Go7iiopora, 

 ■and not unlike the form from Peloua, see G. Gironde 1. It is, however, altogether more 

 reticulate and delicate, with more distinctly porous walls, and the calicles are smaller. Two 

 other forms from Dax are described above : one was said to be dendroid and the other had 

 very large calices, 5-6 mm., and large pali. The specimen that we are discussing looks as if 

 it may have had pali, but, as stated, the original surface is worn away and the section can 

 hardly be trusted to give delinite information on that point. 



The specimen is quite typical and does not show any of the extreme modifications of the 

 majority of the Paris Basin forms. 



a. Geol. Dept. R. 4814. 



121. Goniopora Dax (4)4- 

 [Gaas (Oligocene, Aquitanian), coU. Deshayes ; British Museuni.J 



Description. — Corallum massive and very dense. 



Calicles very minute, about 1 • 20 mm. Walls an open, very angular reticulum, of varying 

 thickness. The septa vary in number, often appearing to be only 12, but so many of these 

 fork before reaching the wall reticulum that there can be no doubt but that the true number 

 is 18-20. The septa, which are not crowded, are angularly bent rather than curved, and 

 frequently witli lateral points here and there, which make the angular character of the septa 

 more pronounced. The interseptal loculi are open and conspicuous. The columellar tangle 

 is composed of the angularly bent ends of the septa fusing to form a rather solid reticular 

 mass. 



In the section the vertical trabecule are conspicuous in the walls, but the rest is a close 

 Teticulum witli round pores and very thin filaments or flakes. 



There is only a small fragment of this coral, without any trace of the original surface. It 

 somewhat approaches those specimens which, but for the forking of the septa, would have 

 to be placed in the genus Porites. See Introduction, p. 21, and for examples, G. Gironde 1, 

 G. Paris Basin 11, and G. France a (Table IV. G, p. 182). 



Geol. Dept. R. 4815. 



122. Goniopora Gironde (2)1. (PI. IX. fig. 5 ; PI. XIV. fig. 8.) 

 [Gironde (Oligocene, Aquitanian).] 

 Description. — Corallum massive, exact growth-form unknown. 



Calicles 1 • 5 mm. across, polygonal, shallow, funnel-shaped, with sharp thread-like ridge 

 Along the wall ; ridge straight or nodulated, wavy and even finely zigzag. 



