CORALS FROM THE CORAL RAG. 103 
Comoseris meandrinoides,! which we know only by M. Michelin’s figures, appears to 
? fo} 
differ from the British fossil here described, by the serpentine form of the ridges, which 
pass without interruption from one edge to the other, and by the septa being more unequal. 
In Comoseris vermicularis’ the ridges are thinner, the septa much more delicate and closer 
5 ? 
set. 
Genus PROTOSERIS.® 
Protoserts Wattonr. ‘Tab. XX, figs. 1, la, 14, le. 
9 US 5) > 
Corallum composite, foliaceous, subcrateriform, sometimes lobate and invaginated. 
The outer surface is formed by a common basal plate covered with delicate, granulated 
costal striae, which are well marked, and project somewhat unequally alternately ; they are 
almost straight, and extend from the central basal point to the edge of the corallum, but 
dichotomise sometimes. ‘This basal plate presents also some transverse constrictions and 
tumefactions, which form ill-defined accretion ridges, but are not strongly characterised. 
The upper (or inner) surface of the corallum 1s almost smooth, and presents neither valleys 
nor ridges, nor cristae, but is covered with shallow calices irregularly disposed. These ca/ices 
are individualised by the existence of a well characterised but shallow central depression or 
fossula, but are not distinct at their circumference where they are completely blended 
together, the septa passing, without any interruption, from one visceral chamber to another 
(figs. la and 14). In the centre of each fossula there exists a small papillose co/wmella, 
formed by the inner septal denticulations. There are from thirty to forty septa round each 
calice, but not more than half of these extend to the fossula; they are small, delicate 
lamin, with a crenulate edge, and are all nearly equal in thickness ; some are straight, 
others more or less bent, or even flexuous, and many of them become cemented to one of 
the adjoining ones at their end, so as to assume the appearance of bifurcation. 
We have seen but one specimen of this remarkable fossil ; it was found in the Coral 
Rag at Osmington, near Weymouth, by Mr. Walton, and communicated to us by that 
active paleeontologist. 
This coral cannot be referred to any of the generical divisions established in the intro- 
duction to this Monograph, but must form the type of a new genus to which we have 
given the name of Protoseris. This genus is closely allied to Ayaricia,‘ Leptoseris,’ 
Cyathoseris,’ Oroseris,’ and Comoseris,* but differs from all by its frondescent lamellar 
Pavonia meandrinoides, Michelin, loc. cit. ; Comoseris meandrinoides, D’Orbigny, Prodr., vol. ii, p. 40. 
Tab. xxiv, fig. 1. 
See our Mémoire sur les Polyp. Palzeoz., etc., loc. cit., p. 129. 
Introduction, page xlix. S Tbs; p-ixlx. Slaps XUK. 
Milne Edwards and J. Haime, Polyp. Palzeoz., ete., p. 131. 8 See p. 131. 
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