38 MADREPORARIA. 



are, however, too corroded to show reliable details. The cross section no longer shows the 

 same striking proportions between axial and cortical regions, the former being here small and 

 central, the larger part of the section being the dense periphery. One seems to be part of the 

 remains of a thin branched specimen 1 cm. thick, with forking at about 90°, the other two of a 

 coral the stems of which were 1 • 5 cm. thick with forkings of 120°. 



ct. Geol. Dept. E. 2559 (part). 



Cj. This may perhaps be a separate fragment of the same coral as Cj. It shows the 

 calicles a little more distinctly with short, stout, wedge-shaped septa abutting irregularly upon 

 a solid wall on which a fine wavy thread can be traced and large rounded pali related to the 

 fusing septa in the typical manner. 



cj. Geol. Dept. R. 2534. 



d. Deserves special mention. It is not only more truly fossilised but shows further 

 differences. The calicles, though apparently corroded and thus with their skeletal elements 

 thickened, are still conspicuous, and the section shows a more uniform, open, but stout network 

 across the whole fracture. The forkings are sharply rectangular, with the internodal stems 

 straight and of nearly uniform thickness (1"5 cm.). The surface layer with its calicles seem 

 to consist of nearly uniformly thick, smooth, skeletal elements arranged as a network of short 

 threfids so grouped as to show calicle areas with stout, continuous, roughly zigzag walls, and 

 the beginnings of radially arranged septa. The majority of the latter are quite short, one or 

 two, however, joining the pali which are an irregular group of smooth, round granules confused 

 with other skeletal (columellar) elements. The calicles were about 1 • 20 mm. in diameter. 



These details hardly represent the original living condition of the coral, as it is almost 

 certain that the finer points of the skeletal elements have been corroded off. 



d. Geol. Dept. R. 2536. 



e. This is a solid block of limestone from Castle Grant, Barbados, with one or more 

 fragments of a branching Pontes embedded in it. The sections seem to have been about 1 cm. 

 in diameter, and show a rather thin, coarse axial reticulum, surrounded by a thick, dense, 

 cortical layer of very stout, irregular skeleton, that is, without any marked differentiation into 

 radial (or trabecular) and concentric elements. 



Geol. Dept. E. 9817. 



16. Porites Barbados 6. (P. Barhatce sexta.) (PL IX. fig. 4.) 



[Barbados (Pleistocene), coll. Franks ; British Museum.] 



Description. — The corallum rises with long, slender, cylindrical and slightly wavy stems, 

 which give off lateral spurs nearly at right angles and at various distances apart. The stems 



