XXXVI BRITISH FOSSIL CORALS. 
Section I1.—ASTREIN AZ CONFLUENTES. 
Corallum massive, increasing by fisstparity, and formed by a series of corallites, the 
individuality of which is not distinct. The calices, thus united in a common trench, have 
their septa arranged in a parallel manner in two lines; and the columella, when existing, 
is continuous in the whole length of the series. 
These meandriform Corals much resemble the confluent Eusmilinee, and in fossils where 
the apical teeth of the septa may be worn away, it is often difficult to distnguish them. — It 
may therefore be useful to mention that, in the confluent Astreime, the gyri are always com- 
pletely united laterally, and never more or less segregate, which is sometimes the case with 
the confluent Eusmilin ; that the columella, which is generally spongy in the latter, never 
presents that loose structure in this section ; and when it is lamellar, the septa are united to 
it by an undivided margin in the confluent Eusmilin, and by a series of trabicule or 
processes in the confluent Astreinze; lastly, that the sides of the septa are more or less 
granulated in all these Astreinze, and are on the contrary almost glabrous in the meandroid 
Eusmiline. 
48. Genus MEANDRINA. 
(Pars) Lamarck, Hist. des Anim. sans Vert., t. ii, p. 244, 1816; Milne Edw. and J. Haime, Comptes rend., 
t. xxv, p. 493. 
Corallum glomerate, adherent by a very broad basis, and having a very dense 
structure. Gyri intimately united by their lateral walls, which constitute simple, compact 
ridges, with a cristate apex. Calicular trenches very long. Co/wmella much developed, 
spongy and essential (that is to say, not arising from the septa, and distinct from the 
bottom of the visceral chamber). Sepéa crowded, enlarging near the columella, and not 
presenting any appearance of a paliform lobe. Plate or exterior common walls of the 
corallum covered with a complete delicate epitheca. 
Typ. sp., Meandrina filograna, Lamarck, loc. cit., vol. ii, p. 248; Michelin, Icon., pl. xi, fig. 7. 
49. Genus MANIcINA. 
(In parte) Ehrenberg, Corall. des Roth. Meeres, p. 101, 1834; Dana, op. cit., p. 188, 1846; Milne Edw. 
and J. Haime, Ann. des Se. Nat., vol. xi, p. 285, 1849. 
Corallum free or sub-pedicellate, in the adult state ; sub-turbmate when young, but 
becoming convex, and massive. G@yri very long, and united by their walls, so as to 
form simple ridges, as in the preceding genus ; the apex of the ridge cristate or sulcate. 
Calicular trench broad and deep. Colwmella spongy, and even more developed than 
in Meandrina. Sepéa thin, crowded, strongly granulated, and armed with delicate, equal 
teeth ; a well-characterised paliform lobe arismg from the edge of the principal septa 
near the columella. P/aée or exterior common wall covered with thin and very delicately- 
serrated coste ; its inferior part having an incomplete epitheca. 
Typ. sp., Manicina areolata, Ehrenberg, loc. eit. ; Madrepora areolata, Ellis and Solander, op. cit., 
tab. xlvii, fig. 5. 
