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ZoOPHYTA.] LOWER PALAEOZOIC RADIATA. 19 1st Family. MILLEPORIDAE. Corallum polymorphous; cell-tubes small, numerous, distinctly walled; lamellae reduced to rudimentary striae, exceeding twelve in number; transverse diaphragms numerous, strong, distinctly separated. Contains the Subfamilies :—1, Milleporince (not found in the Lower Palaeozoic rocks) ; 2, Favositinw; 3, Chcvtetincc; 4, Halysitince. 2nd Subfamily. FAVOSITINW. Corallum massive; cell-tubes of moderate size, in contact; no ccenenchyme; walls perforated by connecting pores; lamellae nearly obsolete, usually forming numerous vertical internal striae. MM. Edwards and Haime place the Pocilloporce in their family Favositidte, but as these have an abundant ccenenchyme, I think they would be better placed with the Seriatopores, with which they seem to agree in structural details, and might be referred to the family Oculinidte. This sub-family contains the following Genera: 1, Favosites; 2, Alveolites; 3, Ccenites; 4, Nebulipora; 5, Michelinea. Genus. FAVOSITES (Lam. restricted.) = Calamopora (Gold.) Gen. Char.—Corallum composed of very numerous tubes, rounded, or prismatic and polygonal (from mutual pressure), traversed by numerous horizontal diaphragms; destitute of vertical radiating lamellae, or internal sulci; sides or angles with distinct communicating pores; young tubes formed by lateral budding or interpolation, mouths of the tubes opening at right angles to their length. Distinguished from Cliatetes by the lateral communicating pores; by the young being added by interpo lation and not by fission or splitting of the old tubes, and, as a consequence of this mode of development, the exterior walls of the tubes being exposed by rough vertical fracture. Favosites alveolaeis (Gold.) Bef. and Syn.—Gold. Pet. Germ. t. 26. f. 1. Id. Lonsd. Sil. Syst. t. 15. bis. f. 2. + Var. a. Favosites multipora. Lonsd. Sil. Syst. t. 15. bis. f. 5. Sp. Ch.—Corallum forming large irregular masses, or small hemispherical expansions, with concen trically wrinkled flattened base, impressed by the rhomboidal slightly oblique bases of the tubes ; tubes from four to six angled, the latter being adult with the average diameter of one line, the former being the young tubes, which are few, and smaller; diaphragms fiat irregularly indented, or undulated at the margins, placed at slightly unequal distances, averaging two or three intervals to the width of a tube; exterior wall of the tubes with four to six vertical, slightly irregular, rows of impressed foramina on each face, the angles of the columns, when not perfectly in contact, connected by small transverse papillate processes about as distant as the diaphragms, varying greatly in prominence, and occasionally absent. The forms of the tubes of this species are not so regular as Mr Lonsdale’s description indicates, but follow the same variations as the F. GotJilandica, the young tubes being, however, less numerous. The great variation in size of the connecting processes on the angles of the tubes in the F. alceolaris has been noticed by Lonsdale, but they have escaped him in what I have no hesitation in considering a variety—his F. multipora ; they are distinct on most specimens, and shew the perfect transition of that species, or variety, to the true F. alveolaris of Goldfuss (which has also several rows of pores on each face of the tube in Goldfuss’s, and part of Lonsdale’s figure). I see no reason for believing the processes on the angles to be perforated. Position and Locality.—Abundant in the impure limestone of Mathyrafal, S. of Meifod, Montgomery shire, and in the conglomerate under the limestone of same place; Llansantfraid, Glyn Ceiriog, Denbigh shire ; Pen y Craig, above Glyn, Llangynyw, Montgomeryshire; Llangynyw Rectory; schists of Golu- goed, Mandinam, Caermarthenshire; sandy schists, Alt Goch, Llanfyllin, Montgomeryshire; and Mid dleton Park, Llandeilo; beds on the lower limestone of Mynydd Fron Frys, five miles W. of Chirk, Glyn Ceiriog, Denbighshire; Cefn y coed Quarry, Glyn Ceiriog, Denbighshire. n 2