INTRODUCTION. XXXI 
30. Genus HerERocentia. 
Milne Edw. and J. Haime, loc. cit., p. 308, 1848. 
Corallum resembling that of Sarcinula, but differmg from all the preceding genera 
by the small number and the unequal development of the sepéa, which form in appearance 
only three systems. In general, one of the three large primary septa is more developed 
than the others, and remains sometimes alone in fossil species. Ca/ices circular, with a 
projecting free margin. No columella nor pali. Septa exsert ; coenenchyma abundant, of 
a foliate structure, and having a granular surface. 
Typ. sp., Heteroceenia exiguis, Milne Edw. and J. Haime, loc. cit., tab. ix, fig. 13 ; Lithodendron exigue, 
Michelin, Icon., Zooph. tab. Ixxu, fig. 7. 
Section [V.—EUSMILIN A IMMERS/AH. 
Corallum composite. Corallites disposed as in the preceding Section, but imbedded in 
an epithecal cellular tissue, and not united by costal laminze or mural annular expansions ; 
gemmation lateral and basal ; reproduction never fissiparous. 
31. Genus SARCINULA. 
(In parte) Lamarck, Hist. des Anim. sans Vert., t. ii, p. 222, 1816; Anthophyllum, Ehrenb., op. cit., 
p. 89, 1834. 
Corallum fasciculate, and almost massive. Corallites tall, free towards their upper end, 
which projects more or less above the surface of the cellular exotheca. Wadls strong, with 
costa but little developed. No columella, or only a rudimentary one. Septa very exsert. 
Dissepiments in general simple, and not abundant. 
Typ. sp., Sareinula organum, Lamarck, loc. cit., p. 223; Milne Edw., Atlas du Régne Animal de 
Cuvier, Zooph., pl. lxxxv, fig. 1. 
Second Tribe—ASTREIN Ai. 
Septa having their upper edge lobulated, dentate, or armed with spines, and often 
imperfect near their inner edge. Coste also spinulous, dentate or crenulate, but never 
forming simple cristae, as is often the case in Eusmilinee. Co/wmella in general spongy, 
rarely lamellar, and never styliform. Corallum in general massive. 
Section I.—ASTREINA) HIRT. 
Corallum simple or composite, and then formed by perfectly delineated corallites, pro- 
duced by fissiparity, or by calicular gemmation. 
