18S6.] MADREPORARIAN CORAL. 129 



there was uo trace of any shell or other foreign body to be detected 

 as was the case with two other species of the same genus as described 

 by Prof. Moseley (1, page 154). From the pedicel radiate costse corre- 

 sponding to the primary, secondary, and tertiary septa. The costse 

 are formed by ridges along which are a series of blunt points. 



Between the basal costse the corallum is granulated, the granules 

 running in lines and corresponding, not to the septa, but to the 

 interstices between them. 



On the side-wall of the corallum, however, the ridges and points 

 become much sharper, and there arise costse corresponding to the 

 quaternary and quinary septa ; these are smooth and do not bear 

 the points with which the primary, secondary, and tertiary costae 

 are provided. 



The single specimen from which this species is described has 

 unfortunately been broken and has re-mended itself, so that it is 

 malformed, for there are only nine larger septa {i. e. primary and 

 secondary) ; no doubt had the specimen been an uninjured one it 

 would have possessed the typical Madreporarian number of twelve 

 (i. e. six primary and six secondary). 



The coral will therefore be described on this assumption. There 

 are five cycles of septa — six primary, six secondary, twelve tertiary, 

 and forty-eight quinary, in all ninety-six. 



The secondary septa are distinguished from the primary by 

 bearing large stout pallial elevations, each septum bearing two, the 

 smaller one being the more central ; the ])rimary septa also bear 

 pali, but they are not so large or distinct as those of the secondary 

 septa. The tertiary septa are also slightly thickened at their inner 

 ends. 



The ends of the primary, secondary, and tertiary septa are all 

 fused with a very thick up-rising of calcareous matter, the columella, 

 which bears five or six rounded projections resembling the true pali, 

 but much lower, showing how the columella has been formed by 

 the central ends of the septa and their pali. This knobby top of 

 the columella forms a floor to the central part of the enteron of the 

 polype, and it is much shallower than the surrounding chambers 

 between the septa, where the floor is formed by the true base of the 

 corallum. 



The quaternary septa do not quite reach the columella, but they 

 are bent inwards so as to touch the tertiaries ; those lying to the 

 immediate left of the tertiary septum being shorter and joining the 

 tertiary septum at a point nearer the circumference than those on 

 the right, as is best seen in the figure (Plate XII. fig. 1). 



The quinary septa are much shorter than the others, only reaching 

 halfway along the base of the theca and ending in two small 

 upgrowths which seem to represent two rudimentary pah ; no 

 rudiments of pali could be seen on the quaternaries. 



All the septa are extremely exsert, the primary and secondary 

 septa more especially so, so that in the specimen the tissuej did not 

 cover their sharp edges ; but this is probably due to the contraction 

 caused by the spirit. 



It is only the outer halves of the primary and secondary septa 

 Proc. Zool. Soc— 1886, No. IX. 9 



