A2 BRITISH FOSSIL CORALS. 
Veretellum, for in the latter the axis is quite rudimentary. We therefore considered it 
advisable to designate this fossil Coral by a peculiar generic name, but we are not as yet 
sutticiently well acquainted with its characters to be able to form a complete idea of the 
polypi to which it belonged. 
Graphularia Wetherelli is the only known species of this genus of Pennatulide ; it 
was discovered about twenty years ago by Mr. Wetherell in the London Clay at Hampstead 
Heath and at Highgate. Mr. Frederic Edwards has also found fragments of it at Barton 
and at Haverstock Hill; and it is to his kindness that we are indebted for the specimens 
described in this Monograph. ' 
Family GORGONIDA. 
Tribe ISIN A. 
1. Genus Morspa. 
1. Mopsea costata. Tab. VII, figs. 3, 3a. 
Corallum arborescent, dichotomous, and composed of epidermic basal sclerenchyma, 
the ossification of which is intermittent, so as to constitute a series of calcified cylinders, 
separated by non-ossified discs. The branches appear to spread out in one plane; they 
are thin, elongated, cylindrical, and deeply fluted longitudinally ; each of them, immediately 
above its separation from the parent branch or stem, is bent outwards and upwards, so as 
to represent an inverted ogival angle. The corneous articulations, which have been de- 
stroyed during the process of fossilization, are very thin, and do not appear to have existed 
in any of the non-bifurcated branches. The longitudinal coste are straight, thick, pro- 
nuinent, denticulated on their sides, and separated by deep furrows. All those belonging 
to the same joint are in general of the same size; but in some of the thickest branches, 
where they are the most numerous (about twelve), some very small ones are sometimes 
visible between the larger ones. The diameter of the thickest branches in the specimens 
here described is about half aline; that of the smallest not more than a tenth of a line. 
The genus Mopsea was established by Lamouroux, but more correctly characterised by 
Ehrenberg, who refers to it four recent species—the MJopsea dichotoma of Lamouroux, 
the MZ. gracilis, M. erythrea, ad M. encrinula, Ehrenberg ; but it is doubtful whether 
the last does in reality appertain to this division of the Isine. Mr. Dana is of opinion 
that the sis coralloides of Lamarck is also a Mopsea; but in all of these species the 
corallum is but slightly striated, and never presents anything like the strong costa which 
exist in the above-described fossil. 
We have seen two specimens of this Gorgonida, found in the London Clay at Holloway, 
by Mr. Frederic Edwards. 
