lxxii BRITISH FOSSIL CORALS. 



30. Genus Lithostrotion. 



(Pars) Fleming, British Animals, p. 508, 1828; Strombodes and Lonsdaleia, M'Coy, in Ann. of Nat. Hist., 



2d series, vol. iii, pp. 10, 11, 1849. 



Corallum resembling Nematophyllum, but having the columella formed by a fasciculus 

 of twisted bands, and the septa subvesicular exteriorly, and joining the columella along 

 their inner edge. 



Typ. sp., Lithostrotion floriforme, Fleming, loc. cit., p. 508. 



31. Genus Axophyllum. 

 Corallum simple, trochoid, and resembling Lithostrotion by its structure. 

 Typ. sp., Axophyllum expansum, nob. 



32. Genus Syringophyllum. 



Sareinula, Dana, Zooph., p. 363, 1846 (not Sarcinula, Lamarck). 



Corallum composite, astreiform. Corallites provided with strong icalls, and much 

 developed costae. Septa large. Tabula but little developed. Columella styliform. 



Typ. sp., Syringophyllum organum ; Madrepora organum, Linnaeus, Syst. Nat., ed. xii, vol. i, p. 1278. 



Family XV. 

 CYSTIPHYLLLDtE. 



Corallum essentially composed of a vesicular tissue, and presenting little or no traces 

 of septa or radiate striae. 



1. Genus Cystiphyllum. 



Lonsdale, in Murchison's Silurian Syst., p. 691, 1839. 



Corallum simple, turbinate ; the visceral chamber filled with small vesicular laminae. 

 Calice shallow. Walls vesicular. 



Typ. sp., Cystiphyllum Siluriense, Lonsdale, loc. cit., tab xvi bis, fig. 1 (but not fig. 2). 



Sub-order 5. 

 ZOANTHARIA CAULICULATA. 



Antipathacea, Dana, Zooph., p. 574. 

 Polypi supported on a sclerobasis or epidermic stem-like corallum. 



