INTRODUCTION. li 



the sclerenchyma, which, instead of forming imperforated lamella as in the preceding 

 groups, is always porous, or even reticulate. In general the mural apparatus constitutes 

 here the greatest part of the corallum, and does not consist of costal laminae ; the walls 

 are always perforated, and completely or nearly completely naked. It is also to be 

 remarked, that the visceral chamber is almost completely open from top to bottom, and 

 never filled up with dissepiments or synapticulae, as in most of the Zoantkaria aporosa, or 

 with tabulae, as will be seen in the next two sections of this order. 



The perforated Zoantharia form three natural families : Eupsammidae, Madreporidae, 

 and Poritidae. 



Family V. 

 EUPSAMMIDAE. 



Milne Edw. and J. Haime, Ann. des Sc. Nat., 3 me serie, vol. x, p. 65, 1848. 



Corallum simple or complex, with well- developed lamellar septa, a spongiose columella, 

 and perforated, granular, subcostulated walls. 



The septa are always numerous, and those of the last cyclum are never situated in the 

 direction of a line drawn from the centre of the calice to its circumference, but are bent 

 towards those of the penultimate cyclum, so as to produce the appearance of a six- or 

 twelve-branched star. The interseptal loculi are completely open from top to bottom, or 

 divided only by a few incomplete trabiculae. The walls have a granulate vermiculats surface, 

 and become often very thick in advanced age, but never constitute . a loose spongy mass, 

 as in Madreporidae and Poritidae, or a compact ccenenchyma, as in Oculinidae. 



The star-like arrangement of the septa, which is visible in transverse sections of these 

 corallums, as well as in the calice, is not met with in any other family. The principal 

 septa are sometimes imperforate, but those of the succeeding cycla are more or less porous. 

 It is also to be noted that there are never any pali, and that the costae are always rudi- 

 mentary ; sometimes there is a rudimentary epitheca. 



1. Genus Edpsammia. 



Milne Edw. and J. Haime, Ann. Sc. Nat., 3 m ° serie, vol. x, p. 77, 1848. 



Corallum simple, subturbinate, free, and not presenting any lateral mural expansions. 

 Calice oval and rather deep. Septa broad, slightly exsert, granulate, closely set, and 

 forming four or five cycla. Costa simple, distinct from the basis of the corallum, nearly 

 equal, slightly vermiculate, and composed of a series of distinct, projecting granulae. 



Typ. sp., Eupsamrnia trochiformis, Milne Edw. and J. Haime, loc. cit., tab. i, fig. 3 ; Madrepora trochi- 

 formis, Pallas ; Turbmolia elliptica, Brongniart. 



