CORALS FROM THE SILURIAN FORMATION. 255 



equal in size, rather thick towards the walls, but very slender towards the centre of the 

 corallites. Diameter of the calices about one third of a line. 



Upper Silurian beds of Dudley. Collection of Mr. J. Gray. 



This species differs from P. petaliformii by the calices being much smaller, and more 

 closely set, and by the septo-costal radii being more regular. 



3. Genus Propora, (p. lix.) 

 Propora tubulata. Tab. LIX, figs. 3, 3a, 35. 



Porites tdbulata, Lonsdale, in Murchison, Silur. Syst., p. 687, pi. xvi, fig. 3, 1839. 

 Astreopora tubulata, Lonsdalei, and grandis, VOrbiyny, Prodr. de Pal^ont., vol. i, 



p. 50, 1850. 

 Pal^eopora tubulata, M'Coy, Brit. Palaeoz. Foss., p. 18, 1851. 

 Propora tubulata, Milne Edwards and Jules Haime, Pol. Foss. des Terr. Palseoz. (Archives 



du Mus., vol. v), p. 224, 1851. - 

 Heliolites eleganb and spinipora? /. Hall, Paleont. of New York, vol. ii, pp. 130, 131, 



pi. xxxvi, figs. 1, 2, 1852. 



Corallmii massive, irregularly convex ; common basal plate covered with a epitheca 

 presenting concentric folds ; upper surface convex or subgibbose. Calices circular, 

 somewhat unequal in size, and surrounded with a slightly prominent edge that is 

 crenulated in consequence of the prolongation of the septa beyond the walls, where they 

 constitute small, thick costa, which are sometimes sufficiently developed to attain those of 

 the adjoining corallites. In general, 12 septa, slightly exsert, rather thick exteriorly, and 

 somewhat unequal in size. Diameter of the calices usually about half a line. 



A vertical polished section shows that the walls are distinct ; the tabulce closely set, 

 concave in the middle, sometimes quite horizontal, and at others irregularly placed ; the 

 space situated between the walls of the adjoining corallites occupied by an abundant, 

 irregular exothecal tissue. Some of the dissepiments composing this tissue are horizontal, 

 and assume the appearance of small extramural tabula?, but others constitute vesicular cells. 

 No traces of the costse are seen in this exothecal mass. 



The specimens here described were from Dudley and Wenlock. The localities 

 mentioned by Sir R. Murchison are Woolhope Valley, Benthall Edge, Ledbury, Woodside 

 near Nashsur, Fownhope, and the west parts of the Malvern Hills, between Asten Ingham 

 and May Hill ; by Professor M'Coy, Aymestry, in Herefordshire ; Altgoch, Llanfyllin, in 

 Montgomeryshire; Golugoed ; Mulock, Dalquorhan, in Ayrshire. The same species is 

 found in Gothland and in Bohemia. 



Specimens are in the Collections of the Museum of Practical Geology, of the Geological 

 Society, of the Museum of Paris, &c. 



1 See tab. lix, fis. 1. 



