INTRODUCTION. XXVil 
in the two preceding genera. No columella. Septa closely set, not remarkably thin, slightly 
exsert, and granulate. Wadls covered with a strong epitheca, reaching almost to the margin 
of the calices. 
Typ. sp., Thecosmilia trichotoma, Milne Edw. and J. Haime, loc. cit.; Lithodendron trichotomum, 
Goldfuss, Petref. Germ., tab. xiii, fig. 6. 
15. Genus BARYSMILIA. 
Milne Edw. and J. Haime, loc. cit., p. 273, 1848. 
Corallum composite, increasing by fissiparity, and forming a very thick stem, on the 
apex of which the corallites become distinct, and are disposed in transverse series. Columella 
rudimentary or not existing. Sepa closely set. Walls very thick, naked, and covered with 
delicate costal lines, which are nearly equal and granulate. 
Typ. sp., Barysmilia Cordieri, Milne Edw. and J. Haime, loc. cit., tab. v, fig. 4. 
16. Genus DENDROSMILIA. 
Milne Edw. and J. Haime, loe. cit., p. 274, 1848. 
Corallum composite, somewhat arborescent, and increasing by lateral gemmation. 
Corallites with large septa, and a spongious columella. 
Typ. sp., Dendrosmilia Duvaliana, Milne Edw. and J. Haime, loc. cit., p. 274. 
17. Genus SvYLOSMILIA. 
Milne Edw. and J. Haime, loc. cit., p. 275, 1848. 
Corallum composite, fasciculate, and increasmg by lateral gemmation. Corallites tall, 
with a small number of thick sepfa, and a styhform columella. Walls thick, with obsolete 
costa. 
Typ. sp., Stylosmilia Michelinii, Milne Edw. and J. Haime, loc. cit., p. 275, pl. vi, figs. 2, 2°. 
18. Genus PLACOPHYLLIA. 
D’Orbigny MSS. 
Corallum composite, segregate, and increasing by gemmation, which is almost basal. 
Corallites cylindrical and low. Columella well developed. Septa probably entire. Wails 
completely covered with a membraniform epitheca, presenting thick transverse folds. 
Typ. sp., Placophyllia dianthus, D’Orbigny MSS. ; Lithodendron dianthus, Goldfuss, Petref. Germ., 
tab. xii, fig. 8. 
Section I1—EUSMILINA| CONFLUENTES. 
Corallum composite, and presenting no separation between the corallites, united in 
rows, so as to assume a meandriform disposition ; multiplication essentially fissiparous. 
