XXVUL BRITISH FOSSIL CORALS. 
19. Genus CYENOPHYLLIA. 
Dana, Zoophytes, p. 169, 1546. 
Corallum pedunculate, but mcereasing very little by its basis, and terminated by a large 
oval, almost flat, calicular surface ; the different series of corallites intimately united together 
by means of their common walls, and without there being in general any ccenenchyma ; the 
gyri or calicular grooves very long, and the mural ridges thin. Colwmella lamellar, and 
almost uninterrupted from one end of the gyrus to the other. In general, some traces of 
pali. Septa rather closely set, slightly exsert, and delicately granulated. Dzssepiments very 
abundant, arched, and oblique; sometimes simple, but m general producing a vesicular 
mass. ‘The common epitheca rudimentary, and covering only the inferior part of the common 
exterior walls, in the upper part of which are cosf@, nearly equal, and more or less cristiform 
near the margin of the calicular surface. 
Typ. sp., Ctenophyllia meandrites, Milne Edw. and J. Haime, Ann. des Sc. Nat., 3™ série, vol. x, p. 277 ; 
Meandrina pectinata, Lamarck ; Madrep. meandrites, Solander and Ellis, Zooph., tab. xlviu, fig. 1. 
20. Genus DENDROGYRA. 
Ehrenberg, Corall. des Roth. Meeres, p. 100, 1834. 
Corallum composite, having the form of a thick, massive, vertical column, in which the 
corallites are placed perpendicularly to the axis, and constitute very tortuous gyri, 
completely united by their walls ; mural ridges broad, flat, and compact ; grooves shallow. 
Columella highly developed, and formed by a series of very compact, enlarged processes. 
Septa very thick and closely set. Dissepiments large, but not crowded. 
Typ. sp., Dendrogyra cylindrus, Bhrenb., op. cit. ; Milne Edw. and J. Haime, Ann. des Se. Nat., 3 série, 
Zool., t. x, pl. vi, fig. 9. 
21. Genus RuIPIDOGYRA. 
Milne Edw. and J. Haime, loc. cit., p. 281, 1848. 
Corallum composed of a single series of corallites and constituting a flabelliform or 
tall tortuous mass, the lateral walls of which are always free from top to bottom. Columella 
lamellar, but almost rudimentary. Septa exsert and crowded,  Dissepiments abundant. 
Coste delicate, in general subcristate near the margin of the calice. No epitheca, or only 
a rudimentary one. 
Typ. sp., Rhipidogyra flabellum, Milne Edw. and J. Haime, loc. cit. ; Lobophyllia flabellum, Michelin, 
Ieon., tab. xviii, fig. 1. 
22. Genus PACHYGYRA. 
Milne Edw. and J. Haime, loc. cit., p. 468, 1848. 
Corallum adherent by a very thick peduncle; gyri with a narrow calicular groove, 
and united by a very broad mass of dense ccenenchyma. Colwmella lamellar. Septa 
crowded. Coste delicate and granulated ; little or no epitheca. 
Typ. sp., Pachygyra labyrinthica, Milne Edw. and J. Haime, loc. cit. ; Lobophyllia labyrinthica, Michelin, 
Icon., pl. Ixvi, fig. 3. 
