Zoorpuyta.| LOWER PALASOZOIC RADIATA. 17 
Position and Locality—Very abundant in the Coniston limestone and calcareous schists ef Coniston, 
Lancashire; also at Mathyrafal, S. of Meifod, Montgomeryshire; and High Haume, Dalton in Furness, 
Lancashire ; in the conglomerates (at junction) of Blain y Cwm, W. of Nantyre, Glyn Ceiriog, and a variety 
in the Bala limestone of Maes Meillion, S. of Bala, Merionethshire. 
Explanation of Figures.—Plate 1. C. fig. 4. Portion of large mass, shewing weathered impressions of 
the surface, natural size from Coniston—Fig. 4a. Stars of ditto, magnified two diameters, shewing the 
lamellze, cellular structure of the diaphragms, and few intervening tubuli—Fig. 44. Side view of weathered 
lamelliferous tubes ; part of large mass natural size. 
PALMOPORA PETALLIFORMIS (Lonsd. Sp.)* 
Ref. and Syn.—Porites petalliformis. Lonsd. Sil. Syst. t. 16. f. 4. 
Sp. Ch.—Corallum forming irregular hemispherical masses, with concave, nearly smooth, concentrically 
wrinkled epitheca on base; upper surface covered with very shallow, circular, floriform cells, about one line in 
diameter; diaphragms distant about two spaces equal to one diameter of the tube, with a flat circular centre, 
and the circumference (one fourth of the diameter) broadly undulated between the twelve petal-like radiating 
lamelle ; stars nearly in contact, the interstices occupied by small capillary prismatic tubules (about five in 
the space of one line). 
In this beautiful species the central flattened part of the diaphragms in the shallow cells seems to have 
been taken by Mr Lonsdale for the tube, and the petal-like undulation between the vertical lamelle, for the 
first row of interstitial tubules. This species is separated from the others, by MM. Edwards and Haime, 
to form the genus Plasmopora, on the supposition that the cell-tubes are united by large vertical radiating 
lamelle, but a very careful examination of several large masses has convinced me that this ground of dis- 
tinction cannot be depended on. 
Position and Locality—In the Coniston limestone of Sunny Brow near Coniston, Lancashire; and the 
impure limestone of Golugoed, Mandinam, Caermarthenshire. 
PALHOPORA SUBTILIS (A/*Coy). 
Ref—MOoy. Annals Nat. Hist. 2nd Series, Vol. VI. 
Sp. Ch.—Corallum forming cylindrical branches, usually one and a half to two lines in diameter ; large 
stellular tubes about one sixth of a line in diameter, and a little more or less than their diameter apart; poly- 
gonal intervening tubuli invisible to the naked eye, usually five between adjacent cell-tubes, or about thirty in 
the space of one line; three cell-tubes with their intervening tubuli in a space of one line; main tubes often 
weathering as separate sulcated columns. 
In the middle of the branches the cell-tubes seem to be parallel and vertical, but diverge rapidly at the 
circumference, to reach the surface; they are very often weathered as separate tubuli, as in the P. subtubulata 
and P. tubulata, and on the other hand they often break away from casts of the surface, leaving so little trace 
among the intervening tubuli, that the surface seems merely shagreened under the lens, and bearing some 
resemblance to the Ptilodictya (Stictopora) fucoides (M°Coy), but the casts of the cells are polygonal instead 
of oval, and far more minute in the present coral. The extreme minuteness of the parts of this species dis- 
tinguish it easily from the P. swbtubulata, to which alone it has any affinity. 
Position and Locality.—Very common in the fine Caradoc Sandstone of Mulock, Dalquorhan, Ayrshire. 
* As these pages were passing through the press, I received MM. Edwards and Haime’s great English Memoir 
on Corals, but at too late a period to profit materially from the new portions not previously published in the Comptes Rendus. 
