The size varies from one fourth of an ounce, to two hundred pounds or more, and the tubes occur of every intermediate diameter, from the fortieth to one fourth of an inch. It is not common to find any two specimens of like form, they are, however, ordinarily more or less turbinate, but are sometimes depressed or compressed, and the tubes rectilinear or excurved, and of various lengths. The dilated summit is not so much the effect of a gradual enlargement of the tubes, as of the frequent and adventitious interposition of young ones, which of course renders the openings of the tubes unequal. The tubes or alveoles, vary in the same coral, being 5 or 6, rarely seven sided, but the hexagonal form is most common; the interior of a tube is divided into a great number of apartments or cells, by approximate transverse septæ, each of the cells appears to be connected with the corresponding cells of the surrounding tubes, by lateral orifices in the dividing paries; these orifices are minute, inequidistant, orbicular, their margins slightly prominent, and forming from one to three longitudinal series on each side of the tube; each row is separated from the adjoining one by an impressed line. By means of these osculi it seems probable that all the animals inhabiting a common coral, were connected together, or had free communication with each other, but whether by means of a common organ as in _Pyrosoma_, _Stephanomia_, &c. or simply by contact as in the aggregating _Salpa_, &c. we have no means of determining. The _striata_ differs from _Madrepora truncata_, Esper. (_F. alveolata_, Lam.) in not being "extùs transversè sulcata." It seems to be allied to _Corallium Gothlandicum_, Amœn. Acad. v. 1. p. 106, and it is possible it may prove synonymous, or very similar to it, when that species becomes better known; the latter has been taken for Basalt, and M. Lamarck when describing it, inquires "Est-ce un polypier?" _Madrepora fascicularis_, of Volck. and Parkin. in common with _F. striata_ and _F. Gothlandicum_, is distinguished by the transverse septa, a character which induced me to refer the species here described to _Favosite_; they seem therefore to be congeneric, as analogy indicates a participation in the character of osculated paries. Amongst the great variety exhibited by this species, we have to remark more particularly the following, viz.: 1st. Alveoles perfectly free, that is, destitute of aciculi or lamellæ, the septa wanting, and sometimes the osculi obsolete. 2d. Alveoles filled almost to the summit with the septa, and resembling those combs of the bee-hive which are filled with honey and covered over. 3d. Paries beset with very numerous, interrupted, alternating, transverse lamellæ, which are denticulated at their tips, and project towards the centre with various degrees of prominence and irregularity.