194 BRITISH FOSSIL CORALS. 
L. avanea much resembles LZ. basaltiforme;* it differs from it by its columella being 
stouter, its septa less numerous and straighter, and its endotheca less condensed. 
4. Lirnosrrotion Portnocki. Tab. XLII, figs. 1, la, 14, le, 1d, le, 1f, ly. 
ASTREA IRREGULARIS, Portlock, Rep. on the Geol. of Londonderry, p. 333, pl. xxiii, 
figs. 3, 4, 1843. (Not Defrance.) 
= — M‘Coy, Syn. of the Carb. Foss. of Ireland, p. 187, 1844. 
AstrEA Portiockt, Bronn, Index Paleont., p. 128, 1848. 
NEMAPHYLLUM cLIstoIpEs, M‘Coy, Ann. and Mag. of Nat. Hist., 2d series, vol. ili, p. 18, 
1849, 
Lirnostrorion PortLocki, Milne Edwards and Jules Haime, Polyp. Foss. des Terr. Palzeoz., 
p. 443, 1851. 
NEMATOPHYLLUM CLIstoIpDEs, M‘Coy, Brit. Paleeoz. Foss., p. 98, pl. ili B, fig. 2, 1851. 
Corallum astreiform. Corallites somewhat unequal in size, prismatic, and completely 
united by their exterior walls, which are thin, but very distinct. Inner wall scarcely 
visible in some of the calices. Septa (22 to 36), very unequally developed alternately, 
not closely set, extremely thin, and slightly flexuous ; the principal ones extending almost 
to the Colwmella, which is large, slightly compressed, and prominent. A vertical section 
shows, that in the exterior zone of the corallites the vesicular dissepiments form 2 or 3 
longitudinal series, and are much inclined inwardly, and that the ¢adwle are well developed, 
much raised in the centre, and somewhat divided exteriorly. Great diagonal of the 
corallites 3 or 4 lines. 
Found at Bristol, Graigbenayth, Wellington, Corwen, in Derbyshire ; and, according 
to Col. Portlock, at Kildress and at Kesh, in Ireland. 
Specimens are in the collections of the Museum of Practical Geology, of Cambridge, of 
Paris, and of M. de Verneuil. 
This species differs from Z. aranea,? and from L. basaltiforme,® by the smaller size of 
the corallites, by its septa bemg stouter and less numerous, and its columella being more 
developed. It differs from Z. ensifer* by the greater development of its walls and from 
L. Al‘Coyanum® by its calices bemg smaller, and more unequal in size, and its septa less 
numerous. 
1 See tab. xxxviii, fig. 3. 2 See tab. xxxix, fig. 1. 3 See tab. xxxviii, fig. 3. 
* See tab. xxxviil, fig. 2. 5 See tab. xlii, fig. 2. 
