R. G. Cavruthers — A Revision of some Carboniferous Corals. 63 



that the animals walked over the muddy flats of a lake or river 

 before they were dry. These tracks occur in the same band of green 

 mud as at Tsikuane and Qalo, with ripple-marks and sun-cracks, just 

 what one sees on the muddy bottoms of many of the large rivers to-day. 

 {To he concluded in the March Number.) 



III. — A llEvisioisr OF SOME Carboniferous Corals.^ 



By E. G. Carruthers, of the Geological Survey. 



(PLATES IV AND V.) 



{Continued from the January Number, page 31.) 



Zapheentis delanouei, M.-Ed. & H. (Plate V, Figs. 5-7.) 



1851. Zaphrentis delanouei, M. -Edwards & Haime : Pol. Eoss. d. Terr. Pal. 



p. 332, pi. V, figs. 2-2e {syn. exclusu). 



1860. ,, ,, M.-Edwards: Hist. nat. d. Corall., t. iii, p. 339. 



1861. ,, ,, de Fromentel : Int. a i'et. polyp, foss., p. 288. 

 1869. ,, ,, Kuntli : Zeit. d. deut. Geol. Gesell., vol. xxi, 



p. 665, pi. xviii, fig. 6. 

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



Terr. Garb. d. 1. Belg., p. 101, pi. x, figs. 6, 6«. ' 

 Cliffordana?MA., p. 105, pi. x, figs. 9, 2a. 

 1905. ,, aff. phillipsi (pars), Vaughan : Q.J.G.S., vol. Ixi, pi. xxii, 



figs. 2, 2«. 



External Characters. 



Corallimi conical and, as a rule, gently curved, though often 

 straight ; a short broad outline is not uncommon.'- The epitheca has 

 well-marked longitudinal ribbing, sometimes obscured by fine annular 

 striations in the neighbourhood of the calyx ; slight constrictions of 

 growth may occur, but there is never an interruption in the continuity 

 of the epitheca. Good figures are given both by Milne-Edwards & 

 Haime and by de Koninck. 



Calyx deep, with a thin rim and steep sides. The major septa 

 are strong, well separated, and very regularly arranged, with 

 a characteristic curvature convex to the fossula. This curvature is 

 not so apparent in adult calices (PI. Y, Eig. 5a) ; it is best seen in 

 young specimens, Avhere also the septa in the two cardinal quadrants 

 are arranged as if overlapping those in the counter quadrants (see 

 de Koninck's figure of Z. Cliffordana, PI. x, fig. 9«, IS'ouv. Eecher.). 

 The inner ends of the major septa are, as a rule, slightly thickened 



1 Commuuicated by permission of the Director of the Geological Survey of Great 

 Britain. 



■^ In a few rare cases the coral may become cylindrical in the final growth stages 

 and the septa then become amplexoid, retreating from the upper surface of successive 

 tabulfe. The commencement of such a stage is indicated in PL V, Fio-. 6. 

 A unique specimen from Tournai, now in the Smwey collection (E.G. 330), shows 

 this habit. It is 4*5 cm. in length, and the cylindrical distal portion mea.sures 

 2-5 by 1"3 cm. No trace of marginal dissepiments appears, either in the longitudinal 

 section or m the calyx. In other species amplexoid septa accompany the acquisition 

 of a cylindrical habit, and fuller reference to the matter will subsequently be given 

 under Ganinia cornucopice, Mich. 



