INTRODUCTION. xxxi 



30. Genus Heteroccenia. 



Milne Edw. and J. Haime, loc. cit., p. 308, 1848. 



Corallum resembling that of Sarcinula, but differing from all the preceding genera 

 by the small number and the unequal development of the septa, 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. Calices circular, with a 

 projecting free margin. No columella nor pali. Septa exsert ; ccenenchyma abundant, of 

 a foliate structure, and having a granular surface. 



Typ. sp., Heteroeoenia exinuis, Milne Edw. and J. Haime, loc. cit., tab. ix, fig. 13 ; Lithodendron exiyue, 

 Michelin, Icon., Zooph. tab. lxxii, fig. 7. 



Section IV.— EUSMILINtE IMMERSE. 



Corallum composite. Corallites disposed as in the preceding Section, but imbedded in 

 an epithecal cellular tissue, and not united by costal laminse 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. Walls strong, with 

 costae but little developed. No columella, or only a rudimentary one. Septa very exsert. 

 Dissepiments in general simple, and not abundant. 



Typ. sp., Sarcinula oryanum, Lamarck, loc. cit., p. 223 ; Milne Edw., Atlas du Regne Animal de 

 Cuvier, Zoopb., pi. lxxxv, fig. 1. 



Second Tribe— ASTREIN^E. 



Septa having their upper edge lobulated, dentate, or armed with spines, and often 

 imperfect near their inner edge. Costa also spinulous, dentate or crenulate, but never 

 forming simple cristas, as is often the case in Eusmilinae. Columella in general spongy, 

 rarely lamellar, and never styliform. Corallum in general massive. 



Section I.— ASTREINtE HIRT^E. 



Corallum simple or composite, and then formed by perfectly delineated corallites, pro- 

 duced by fissiparity, or by calicular gemmation. 



