250 BRITISH FOSSIL CORALS. 



and of equal size ; their diameter about one eighth of a line. Diameter of the calices about 

 two thirds of a line. 



This species has been found in the inferior Silurian beds at Applethwaite and Caradoc. 

 Sir R. Murehison has found it also at Marloes Bay, in Pembrokeshire. It exists also in the 

 upper Silurian deposits at Wenlock and Dudley; and in Ireland. The British localities 

 mentioned by Sir R. Murehison as presenting this fossil, are — Aymestry, Rutter Edge, 

 VV^enlock Edge, Lincoln Hill, Benthall Edge, Haven near Aymestry, Lindell's Park, 

 the Ledbury, Delves Green, and Walsall. Professor M'Coy points out its existence in the 

 Ooniston limestone of Long Steddale, Westmoreland; and in Galway, Kerry, Mayo, and 

 Dublin. It is also met with at Nehou and Vire, in France ; in Gothland, in Russia, and in 

 North America. Mr. Hall has recently found it in the Niagara limestone at Lockport, and 

 at Milwaukie, Wisconsin. 



H. interstincta much resembles II. porosa} with which many authors have confounded 

 it ; but it differs from that species by the calices being much more closely set, and by the 

 polygonal divisions of the ccenenchyma being proportionally much smaller. 



We are inclined to think that the fossil corals which Professor M'Coy mentions as 

 being extremely abundant in the calcareous schists and limestone of Craig Head, Ayrshire ; 

 Girvan ; and in the fine Caradoc limestone of Mulock Quarry, Dalquorhan, Ayrshire, and 

 designates under the name of Palaopora favosa, 2 are ill-preserved specimens of the above- 

 described species, 



2. Heliolites Murchisoni. Tab. LVII, figs. 6, 6a, 6b, 6c. 



Fungites, Thomas Pennant, Philos. Trans., vol. xlix, 2d part, p. 513, tab. xv, fig. 2, 1757. 

 Compound madkeporite, Parkinson, Org. Rem. of a Form. World, vol. ii, pi. vii, fig. 10, 1808. 

 Pal^eopora interstincta, var. subtubulata, M'Coy, Brit. Palseoz. Foss., p. 16, pi. i c, 



fig. 2, 1851. 

 Heliolites Mukchisoni, Milne Edivards and Jules Haime, Pol. Foss. des Terr. Palseoz. 



(Arch, du Mus., vol. v), p. 215, 1851. 



Corallum composite, massive, irregularly circular ; its upper surface convex, and its 

 under surface in general free, and presenting strongly-marked circular rugose ridges. 

 Calices equally developed in the same specimen, and varying but little in size in different 

 specimens ; about half a line in diameter ; their margin very thin, and scarcely exsert, but 

 quite distinct from the surrounding ccenenchyma ; and in some of the well-preserved 

 corallites, 12 small septa, somewhat unequally developed alternately, are visible. The 

 calices are not closely set, and vary in their degree of approximation ; the space between 



1 See tab. xlyii, fig. 1 . 



* British Palseoz. Fossils, p. 15, tab. i c, fig. 15.— Ann. and Mag. of Nat. Hist., 2d series, vol. vi, 

 p. 285 (1850). 



