^{page 406 note 1} For Plate XIV. see Geol.Mag., 08, Vol. III., p. 356.Google Scholar

^{page 409 note 1} Die Silurische Fauna des Westlichen Tennessee, p. 73, Pl. v. figs. 1 a–e.Google Scholar

^{page 409 note 2} Eine Kleine grobfaltige Abanderung (of Spirifer trapezoidalis) nannte Defrance Calceola heteroclyta.”Quenstedt. Handbuch der Petrefactenkunde, p. 479.Google Scholar

^{page 410 note 1} A Cystiphyllum, having a shape between a cylinder and a four-sided prism, comes near to the pyramidical form of Goniophyllum.

^{page 410 note 2} Sir Charles Lyell, in the sixth edition of his Manual, says (p. 537) that some naturalists have lately referred C. sandalina to a coral. “ They suppose it to be an abnormal form of the order Z. rugosa, differing from all other corals in being furnished with a strong operculum.” In this opinion 1 cannot join, because, as 1 have endeavoured to show, I do not consider Calceola sandalina, or the other Rugosa, as corals. Neither is the C. sandalina an abnormal form of its order.Google Scholar

^{page 410 note 3} The best figures of C. sandalina are in all probalility those seen in Goldfuss's Petrefacta Germaniæ, vol. ii., pl. clxi. fig. 1.Google Scholar

^{page 411 note 1} Rhizophyllum, n. gen.; Testa semieonica, appendicibus radiciformibus instructa, structura interna cellulosa, calyx vesiculosus, in fundo fossa septali, septis perexiguis. Operculum nucleo centrali, areâ prætenui, in superficie interiori dente medio valido, foveâ. ovali superaddita, dentibus lateralibus nullis. Species unica R. Gotlandicum, F. Roemer, in divisione suprema formationis Siluricæ in Gotlandia reperta. Calceolœ, or rather forms resembling Calceolœ, are by no means characteristic of the Devonian formation, as such also are found in the Lower Silurian strata of Western Gotland in the mainland of Sweden.

^{page 412 note 1} Mémoires, vol. iii., p. 510, plate 52.Google Scholar

^{page 413 note 1} Prof. Steenstrup joins the Zoantharia tabulata with the Rugosa and says that he has also specimens of them (“Calamopora” I.e.) with opercula in situ. Amongst the Favositidœ and similar forms so very common in the Isle of Gothland I never found true opercula, but tubes or cellulæ apparently having an operculum. On specimens of Favosites Forbesi (PI. xiv. fig. 24) and also on others (as, for instance, a new Fletcheria) many tubes are frequently seen closed, or as it were, covered by a calcareous substance, consisting of concentrated lines of growth. This false operculum originated in quite a different manner from a true one. It is formed from borders of the tube growing towards its centrum, the central strata are the youngest. In many tubes, for instance, the centre of this apparent operculum is open. It is also impossible to discern any line of separation between the tube and the operculoid covering.

^{page 414 note 1} Only two Actinozoa (Zoanth. perforate), Protarœa vetusta and P. Verneuili are cited by M. Edwards as found in the Silurian strata of North America. Palœocyclus porpita is also often cited as an exception (Agassiz, , Contrib. iii. p. 128. Morton. “Geologist,” 1863, p. 466Google Scholar) and is placed amongst the Fungidœ. But its compact and solid shell, not at all perforated as in those whose septa alternate with the exterior folds (“costæ”), and do not continue outwards through the walls of the shell, give it a place in the Z. rugosa and in the vicinity of the genus Heliophyllum. As Palœocyclus, during its youngest state, has been attached to other bodies with its apex, it is evident that it cannot be considered as an operculum.