INTRODUCTION. XV 
formed by processes that appear to arise from the lower part of the mner edge of the 
septa. Padi in general lobulated at their apex, narrow, tall, and appearmg also to proceed 
from the inferior part of the margin of the septa, their size diminishing as they approach 
nearer to the columella. Sep¢a nearly equal, very slightly exsert, and closely set, their lateral 
surface strongly granulated, and presenting sometimes traces of imperfect dissepiments ; 
four or five cycla; systems equally developed. Coste nearly equal, straight, closely set, 
projecting very little, and delicately granulated. 
Typ. sp., Paracyathus procumbens, Milne Edw. and J. Haime, loc. cit., tab. x, fig. 6. 
12. Genus Hererocyataus. 
Milne Edw. and J. Haime, loc. cit., p. 323, 1848. 
Corallum simple, sub-cylindrical, extremely short, and adherent by a basis at least as 
broad as the calice, but appearing free, because in the adult state it imbeds in its tissue the 
small shell to which it is fixed. Ca/ice circular, or nearly so, with a broad, deep fossula ; 
Columella small, and composed of very slender vertical styli. Pa/i broad, thin, and denti- 
culate. Septa very exsert, broad, thick, and covered with conical granulations arranged in 
radiate series ; four or five cycla, the last of which is more developed than the penultimate 
one, and composed of septa that diverge from the older septa as they advance towards the 
centre of the visceral chamber. Coste straight, thick, closely set, and strongly granulated. 
Typ. sp., Heterocyathus equicostatus, Milne Edw. and J. Haime, loc. cit., tab. x, fig. 8. 
13. Genus DELTocyYATHUS. 
Milne Edw. and J. Haime, loc. cit., p. 325, 1848. 
Corallum short, conical, free, and presenting no trace indicating its having been 
adherent when young. Calice circular, and almost flat. Co/wmella wultipartite. Pali highly 
developed, and very unequal, those of the penultimate circle the largest, and turned towards 
those of the antepenultimate row, so as to form with them a series of delta. Septa slightly 
exsert. Coste straight, unequal, distinct down to the basis of the corallum, and strongly 
granulated, so as to assume a moniliform appearance. 
Typ. sp., Deltocyathus italicus, Milne Edw. and J. Haime, op. cit., tab. x, fig. 11; Stephanophyllia 
italica, Michelin, Icon. Zooph., tab. vi, fig. 3. 
14. Genus 'TRoprpocyaTHts. 
Milne Edw. and J. Haime, loc. cit., p. 326, 1848. 
Corallum simple, free, presenting no trace of former adherence, compressed, and having 
at its basis a large, thick, transverse, vertical crest, or two projecting lobes, resembling 
wings, or the fins of sepia. Calice elliptic and arched, its small axis bemg much higher 
than its long axis; fossula not very deep. Col/wmel/a oblong and multipartite. Pali entire ; 
those corresponding to the penultimate cyclum of septa taller and broader than the others. 
Septa exsert ; the six systems equally developed. Coste well marked, especially at the 
upper part of the wall, and covered with small granulations. 
Typ. sp., Tropidocyathus Lessonii, Milne Edw. and J. Haime, loc. cit.; Mlabellum Lessonii, Michelin, 
in Guerin’s Mag. de Zool., 1843, tab. vi. 
