R. G. Carntthers — A Revision of some Carboniferous Corals. 25 



Zaphsentis omaliusi, M.-Ed. & H. (Plate IV, Figs. 1-4.) ^ 

 1851. Zaphrentis o?naliusi, M.- Edwards & Haime : Pol. Foss. d. Terr. Pal., 



p. 337, pi. V, figs. 3, 3ff. 



1860. ,, ,, M.-Edwards: Hist. Nat. d. Corall., t. iii, p. 344. 



1861. ,, ,, de Fromentel : Int. a i'et. polyp, foss., p. 289. 

 1872. ,, ,, de Koninck : Nouv. Eecher. sur Aiiini. Foss. d. 



Terr. Carb. d. 1. Belg., p. 94, pi. ix, figs. 4, 4^. 

 Hadrophylhim JEdwardsiamim, ibid., p. 52, pi. iv, figs. 2, 2a. 

 1905. Zaphrentis aff. Fhillipsi (pars), Vaughan : Q.J.G.S., vol. Ixi, p. 269, 



pi. xxii, figs. Ic-e. 



ExTERifAL Characters. 



Corallum gently curved and conical, in the adult portion much less 

 so, sometimes becoming almost cylindrical. There is longitudinal 

 ribbing on the epitheca, more strongly marked towards the tip of the 

 coral; round the calj'x this may be supplemented by fine annular 

 striations (PI. lY, Fig. 2). Slight constrictions of growth are 

 present, but ' rejuvenescence,' in the sense of an interruption in the 

 continuity of the epitheca, never occurs. Excellent figures are given 

 both by Milne-Edwards & Haime and by de Koninck. 



Calyx deep, with abruptly descending sides. In young specimens 

 a quadrate division of the septa within is well seen, four fossulfe being 

 visible {Hadrophylliim Edwardnanuvi, de Kon.), but in the adult the 

 septa usually have a very radial arrangement, with only one break, 

 due to the shortness of the cardinal septum. Frequently, however, 

 both cardinal and counter fossulte are visible even in the adult ; 

 the former always lies on the convex side of curvature of the corallum. 

 A good figure is given by Milne-Edwards & Haime. That of 

 de Koninck is poor in perspective. 



The major septa are strong, reaching to the centre of the calicinal 

 floor, where they are slighth' flexuous, thickened, and fused together, 

 though still distinct from each other. They taper quite gradually up 

 to the rim of the calyx. 



The minor septa are entirely rudimentarj^ only appearing as low 

 ridges between the thickened bases of the major septa. 

 Average dimensions. 



Height of an adult specimen, 2-3 cm. ; diameter of calicinal rim, 

 1"2-1'5 cm. ; depth of calyx, 1-1 '3 cm. 



Internal Characters. 

 . (a) Transverse Sections. — The disposition of the major septa is far 

 more readily seen in cross sections than in the calyx. They are seen 

 to characteristically possess a curvature concave to the cardinal fossula. 

 In sections across tlie adult portions of a corallum this curvature is 

 sometimes not so marked, and occasionally a certain number of the 

 septa may even be bent in the opposite direction for a portion of their 

 length (PI. IV, Fig. 4). The lobing and close interfusion of their 

 inner ends gives rise to a dense mass in the centre of the section. 

 This feature is not constant, however ; examples may be found where 

 the septal ends are not thickened and only join in the very centre of 

 the coral. 

 . The rudimentary minor septa only appear in sections across the 



1 Plates IV aud V will appear iu Februar}-. 



