A monograph of the British fossil corals - kreidefossilien.de

xliv
BRITISH FOSSIL CORALS.
deep. Columella papillose, well developed. Sq)ta thin, not exsert ; the principal ones
having their upper margin almost entire, the others strongly dentated. IFalls covered with
a complete epitlieca.
Typ. sp., Angia rubeola, Milne Edw. andJ. Haime, Ann. des Sc. Nat., 3"" serie, vol. x, tab. vii, fig. 6 ;
Bendrophrjllia rubeola, Quoy and Gaimard, Astrolabe, Zoopli., tab. .xv, figs. 12-15.
75. Genus Crtptangia.
Milne Edw. and J. Haime, Comptes rend., t. xxvii, p. 496, 1848.
Corallnm composed of agglomerate, cylindro-turbinate corallites, which appear to multiply
by gennuation on a non-persistent, soft stolon, so that they cease to be organically
united when in the adult state, but remain imbedded in an extraneous mass composed of
Cellepora. Caliccs cii'cular, with a well-formed fossula. Columella papillose, well developed.
Septa thin, not very closely set ; the upper edge of all of them dentate. IFalls covered
with a complete epitlieca.
Typ. sp., Crijptanyia Woodii, Milne Edw. and J. Haime, loc. cit. ; Cladocora cariosa. Wood, Ann. of
Nat. Hist., vol. xiii, p. 12.
7(). Genus Rhizangia.
Milne Edw. and J. Haime, Comptes rend., t. xxvii, p. 496, 1848.
Corallum increasing by the gemmation of stolons, which sometimes become cahcified,
and are persistent. Corallifes agglomerate, sub-cylindrical. Caliees circular ; fossida shallow.
Columella papillose, and not very distinct from the ueighbouring denticulations of the
septa. Septa thin, scarcely exsert, nearly equal, very closely set, with the upper edge
slightly arched, and armed with small, regidar teeth. Walls covered with a complete
epitheca, which extends almost as high as the apex of the septa.
Typ. sp., Rhizangia brevissima, Milne Edw. and J. Haime, Ann. des Sc. Nat., 3"° serie, vol. x, t. vii,
figs. 7, 8 ; Astrea breviscima, Deshayes, in Ladoucette, Hist, des Hautes Alpes, tab. xiii, fig. 13.
77. Genus Astrangia.
Milne Edw. and J. Haime, Comptes rend., t. xxvii, p. 496, 1848.
Corallum mcrusting. Corallifes very short, produced by gemmation on a thin,
common, basal expansion, the surface of which is granulated. Caliees circular, with a
deep fossula. Columella papillose, sub-echinulate and not distinctly delimitated. Sejjta
thin, exsert, nearly equal, graimlate, and armed with teeth much resembling those of the
columella; the tertiary septa bent towards those of the second cycla, and united to them.
Bissepimenfs in general simple and distant. JFalls naked, with broad, dehcately-granulated
costse.
Typ. sp., Astrangia Michelinii, Milne Edw. and J. Haime, Ann. des Sc. Nat., 3"'^ serie, vol. x, t. vii, f. 5.
78. Genus Phyllangia.
Milne Edw. and J. Haime, Comptes rend., t. xxvii, p. 497, 1848.
Corallum differing from those of the preceding genus l)y the structure of the septa,
the upper edge of which is almost entire in the principal cycla, and shghtly denticulated in
the others. Columella rudimentary.
Typ. sp., PhjUatigia americana, nob.