When living, the solid stony polyparium is enclosed in the gelatinous mass by which it was secreted, and there are numerous tentacula around the central cavity, or sac. These zoophytes may be compared to the _Actiniæ_, or Sea-Anemones, from which they differ only in having a calcareous axis, while the Actiniæ have a tough albuminous integument. (_Wond._ pl. vi. _fig._ 15, represents the living animal; and _Lign. 141, fig. 2_, p. 641, and _Lign. 58, fig. 4_, two fossil species).[236] [236] Fungia numismalis. Pict, Atlas, pl. xxxvi. _fig._ 6. ------ polymorpha. Ibid. pl. xliii. _fig._ 1--4; pl. xlv, _fig._ 11. Anthophyllum Atlanticum. _Lign. 88. fig. 4._--In the arenaceous strata of the United States, which the researches of Dr. Morton, of Philadelphia, have proved to be the equivalents of the European Cretaceous formation, a single lamellated coral is not uncommon. It is evidently related to the Fungiæ, and has been named as above by Dr. Morton. Turbinolia Königi (_Wond._ p. 320).--Polyparium turbinated, striated externally, detached, base not adhering; cell single, radiated. This genus occurs in all the fossiliferous deposits: a small, well-marked species is frequently met with in the Galt, of which subdivision of the cretaceous strata it is a characteristic fossil. It is figured _Wond._ _Lign. 58, figs. 1, 2_.[237] [237] Turbinolia complanata. Ibid. pl. xxxvi. _fig._ 9. ---------- mitrata. Ibid. pl. xxxvi. _fig._ 10. Caryophyllia centralis (_Lign. 89 figs. 1, 2_: _Lign. 88, fig. 5_).--Polyparium turbinated, or cylindrical, simple or branched, longitudinally striated, fixed by the base; cells lamellated.[238] [238] Monocarya (of Lonsdale), Dixon's Fossils, p, 244. A small recent species (_C. cyathus_), is very common in the Mediterranean, and frequently seen in collections: it is cyathiform, and the base by which it is attached to other bodies, is broad and spreading; the newer tertiary deposits of Sicily contain this species in abundance. A Caryophyllia, bearing a general resemblance to this species, is common in the chalk, and occurs in beautiful preservation (_Wond._ _Lign._ 58, _fig._ 3).[239] [239] C. centralis, Pict. Atlas, pl. xxxvi. figs. 15, 16. C. annularis, ibid. pl. xxxvii. _fig._ 5. Branched Caryophylliæ are found in the Coralline Oolite and Dudley Limestones (_Sil. Syst._ pl. xvi.). A large proportion of the Coral-rag of the Middle Oolite is composed of a branched species (_C. annularis_) of this genus; _Lign. 88, fig. 5_, represents a specimen from near Faringdon. [Illustration: Lign. 86. Favosites polymorpha. (Goldfuss.) _Devonian limestone. Eifel._ Fig. 1.--Portion of a branch of the coral; _nat._ 2.--Fragment, slightly magnified, with part of the surface broken away below, exposing the central axis, and radiated arrangement of the cells, with their lateral pores. 3.--Another portion, magnified, showing the polype-cells hollow. ]