120 BRITISH FOSSIL CORALS. 



This species was found in the Great Oolite at Hampton cliffs, by M. Walton. It is 

 easily distinguished from the other species belonging to the same genus by the delicacy 

 and the great number of its septa relatively to the small size of its calices. 



4. Thamnastrea Waltoni, Tab. XXIX, figs. 4, 4«. 



Corallum arborescent. Calices closely set, somewhat unequal. Walls subpolygonal, 

 and becoming apparent when the upper sm'face of the corallites has been worn away. 

 From twenty to twenty-four septa, varying a little in breadth and size alternately, but 

 almost all of the same thickness ; in general strongly bent, and very thick where they 

 pass from one corallite to another, but thin towards the fossula ; their upper edge appears 

 to be almost entire, and their lateral surfaces but feebly granulated. Fossula well cha- 

 racterised. Columella tubercular. Diameter of the calices two-thirds of a line. 



We have seen only a small cylindrical fragment of this fossil that was found by 

 Mr. Walton in the Great Oolite, near Bath. It is very nearly allied to T. Cadomensis} 

 but appears to differ from that species by the smaUness of its calices, and by its septa 

 being thicker and less numerous. The same characters distinguish it from T. Lyelli^ 

 T. apnis^ and T. dendroidea^ to which it resembles by general form of the corallum. 



Prof. M'Coy^ refers to the Astrea gracilis of Goldfuss,^ a cast of which was found 

 at Minchinhampton, and belongs to the Cambridge Museum. There is also in Mr. 

 Bowerbank's collection a specimen of the same kind, from the environs of Bath. These 

 corals all belong to the genus Thamnastrea, but the specimens that we have seen are not 

 in a sufficiently good state of preservation to enable us to characterise them specifically. 



FamUy FUNGIDtE, (p. xlv.) 

 Genus Anabacia, (p. xlvii.) 



An abaci A ORBULITES, Tab. XXIX, figs. 3, 3r/, 2>h, 3 c, 3 c/, 3e. 



Button stone, R. Plot, Nat. Hist, of Oxfordshire, p. 139, tab. viii, fig. 9, 1676. 

 PoRPiTE, Knorr and Walch, Rec. des Monum. des Catastr., v. ii, p. 23, tab. F 3, figs. G, 7, 1 775. 

 Madrepora porpites, W. Smith, Strata identif. by Org. Fossils, p. 30, Upper Oolite, 



fig. 4, 1816. 



^ Michelin, Icon. Zoopb., tab. liv, fig. 14. 



2 Tab. xxi, fig. 4. 



2 Milne Edwards and Jules Hairae, Ann. So. Nat., s. iii, vol. xii, p. 198. 



* Astrea denilroidca, Lesauvage, loc. cit., pi. Ix.wiii, fig. 6. 



^ Ann. of Nat. Hist., s. ii, vol. ii, p. 418. 



^ Petrcf. Germ., v. i, tab. x.xxviii, fig. 13. 



