190 BRITISH FOSSIL CORALS. 



5. Genus Lithostrotion. 1 

 1. Lithostrotion basaltiforme. Tab. XXXVIII, figs. 3, Sa, 3b. 



Lithostrotion, Laid, Litbophyllacii Britannici Ichnographia, epistola 5, tab. xxiii, 1760. 



— Parkinson, Org. Rem., vol. ii, pi. ix, figs. 3 and 6, 1808. 



Astrea basaltiformis, Conybeare and William Phillips, Outlines of Geol. of Engl, and 



Wales, p. 359, 1822. 

 Astrea arachnoides, Befrance, Diet. Sc. Nat., vol. xlii, p. 383, 1826. 

 Lithostrotion striatum, Fleming, Brit. Anim., p. 508, 1828. 

 Columnaria striata, De Blainville, Diet. Sc. Nat., vol. Ix, p. 316, 1830. — Man. d'Actin., 



p. 360, pi. lii, fig. 3. 

 Lithostrotion striatum, S. Woodward, Syn. Table of Brit. Org. Rem., p. 5, 1830. 

 Cyathophyllum basaltiforme, Phillips, Geology of York, vol. ii, p. 202, pi. ii, figs. 21, 22, 



1836. 

 Columnaria striata, Milne Edwards, Ann. de la 2de edit, de Lamarck, vol. ii, p. 343» 



1836. 

 Astrea hexagona, Portlock, Rep. on tbe Geol. of Londonderry, &c, pp. 332, pi. xxiii, 



fig. i, 1843. 

 Astrea basaltiformis, Ibid., p. 333. 

 Lithostrotion striatum, M'Coy, Syn. Carb. Foss. of Irel., p. 188, 1844. 



— microphyllum ? Keyserling, Reise in Petscbora, p. 156, tab. i, fig. 2, 1846. 

 Nemaphyllum minus, M'Coy, Ann. and Mag. of Nat. Hist., 2d series, vol. iii, p. 17, 1849. 

 Lithostrotion basaltiforme and Microphyllum, D'Orbigny, Prodr. de Pal., vol. i, 



p. 159, 1850. 



— — Milne Edwards and Jides Haime, Pol. Foss. des Terr. Pal., 



p. 441, 1851. 

 . Nematophyllum minus, M'Coy, Brit. Palseoz. Foss., p. 99, pi. iii b, fig. 3, 185 1 . 

 Stylastrea basaltiformis, M'Coy, ibid., p. 107. 



Corallum composite, astreiform. Corallites prismatic, and completely united by their 

 walls. Calices very unequal in size. A horizontal section shows that the outer walls are 

 very thin and distinct, and that the existence of the inner walls is indicated only by the 

 limit of the vesicular dissepiments which occupy the exterior zone of the interseptal loculi. 

 Columella small and compressed, but slightly inflated in the middle. Septa rather closely 

 set (40 or 50), very thin, delicately flexuous, and varying somewhat in size alternately; the 

 largest only extend near to the columella. Great diagonal of the calices 6 or 8 lines ; 

 diameter of the zone occupied by the inner wall, 2| or 3 lines. 



The British specimens here described were found at Bristol, Norfolk, and Kendal. 

 Professor Phillips mentions the existence of the same species at Ribble Head, Moughton 

 Scar, Hesket, Newmarket, and Wrekin; and Colonel Portlock, at Desertmartin, Derry, and 



1 See ' Pol. Foss. des Terr. Palseoz.,' p. 432. 



