CORALS OF THE LONDON CLAY. Al 
Orper 2.—ALCYONARIA. 
Family PENNATULID &. 
Genus GRAPHULARIA. 
GrapHuLaRIA WerHERELLI. ‘Tab. VII, figs. 4, 4a, 46, 4c, 4d, 4e. 
Pennatuta, J. Decarle Sowerby and Wetherell, in Geol. Trans., 2d series, vol. v, part 1, 
p. 136, tab. viii, fig. 2a, 6, 1834. 
Corallum styliform, straight, very long, cylindroid towards the lower extremity, sub- 
tetrahedral at the upper part, and presenting on one side a broad shallow furrow. Surface 
appearing smooth, when examined by the naked eye, but showing, when placed under the 
microscope, a multitude of small, longitudinal, closely-set, striee, that seem to indicate a 
fibrous structure. Transverse section showing the existence of a thin coating and a 
radiate structure in the body of the Coral. Diameter of the thickest part, two thirds of a 
line; probable length, more than a foot. 
We have only seen small fragments of this styliform Coral, that evidently constituted 
the central stem of some aggregate polypi of the family of the Pennatulide. Some of 
these broken remains are almost cylindrical, and usually thicker than others that are 
imbedded in the same mass of clay, and have a sub-tetrahedral form ; others, again, are 
intermediate between the former, both by their size and their form, and have the same 
radiate structure and striated surface. It is therefore probable that they all belonged to 
the same species, and constituted a long, slender, sclerenchymatous axis, somewhat similar 
im form to that of Pennatula, but resembling that of Virgularia by its structure. The 
characters of the corallum thus reconstructed are also nearly allied to those of Pavonaria 
and Umbellularia, but differ from those of all the known recent genera of Pennatulide. 
It is brittle, and presents a radiate section, as in Virgularia, but is not cylindrical from one 
end to the other, as is the case in the latter, nor is it from top to bottom of a tetrahedral 
form, as in Pavonaria; it never appears to be twisted like the stem of Umbellularia ; it 
united in its different parts the two forms that are found separately in the two first- 
mentioned genera, and so far resembles Pennatula ; but in the latter the square portion is 
situated towards the lower end, and the apex is cylindrical, whereas in the above-described 
fossil, it is the upper slender part that presents a square section, and the thick basal part is 
cylindrical ; it must also be remembered that the axis of Pennatula is not very brittle, and 
does not present a radiate structure when cut transversely, but appears rather of a fibrous 
structure. Inthe recent genus Lithuaria, the styliform axis is tapering towards the lower 
end, and inflated, pitted, and even somewhat echinulate at its upper extremity. It is also 
impossible to refer the elongate stem of our London Clay Pennatulida to the genus 
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