ANATOMY OF THE MADREPORAKIAN CORAL FUNGIA. 297 



Wilkes' Exploring Expedition/ he gives descriptions of several 

 species, witli drawings of the hard parts and the living animals. 

 To the latter I shall have occasion to refer further on. The 

 family thus established was made the subject of a memoir by 

 Milne-Edwards and Haime, in which many new species were 

 described, and the characteristic features of the corallum were 

 noted. The same authors give a full description of the family 

 in the ' Histoire des Coralliaires/ but confine themselves to 

 the study of the corallum throughout. Professor Martin 

 Duncan has lately published a memoir on the same family, 

 dealing especially with the hard structures, and to his account 

 I have little or nothing to add. The following description of 

 the corallum is taken principally from his paper (5). 



The corallum is simple and discoid al, the base usually rather 

 concave, and the upper surface convex. The theea is distinct 

 and confined to the basal surface ; it is continuous in the cen- 

 tral part of the disc, but in its more peripheral parts it is per- 

 forated by numerous apertures, which lead through it into the 

 interseptal loculi. The septa are numerous, arranged in seven 

 cycles in the moderately large forms, and are continuous; the 

 free margins of the septa are dentate. The theca is orna- 

 mented with radiating rows of spines, each row corresponding 

 in position with a septum above, and representing a costa. 

 The axial fossa is elongate and shallow. The columella is tra- 

 beculate and rudimentary. Special structures named synap- 

 ticula are characteristic of the Fungidje ; they consist of nearly 

 vertical or curved rows of bars, bridging over the space between 

 and connecting the lower portions of two contiguous septa. 

 By them the lower parts of the interseptal loculi are divided 

 up into nearly vertical channels, bounded on two sides by 

 synapticula, and on the other two by the septa. Excellent 

 figures of the synapticula are given by Professor Duncan. 



The flat discoid shape of Fungia is not a characteristic of 

 the genus, but occurs in other groups of the Madreporaria, 

 e.g. Deltocyathus among the Turbinolidse, Stephano- 

 phyllia and Leptopenus among the Eupsammida3. The 

 flat shape is a secondary effect produced by the mode of 



