MADUEPOBAEIAN I'AMILT — THE FTJNQIDiE. 153 



A section of a corallum was made across the lengtli, aud the 

 septa were carefully separated. The larger septa are higher tlian 

 the others, and are marked on their sides (faces) by very regular 

 vertical or slightly oblique, rather close, narrow and low, faint 

 ridges, which carry, at close and regular intervals, distinct sharp 

 granules with a broad base. In some places the ridges are want- 

 ing, and the granules exist in regular series all the same. In 

 other places the ridges exist without the granules. Here and 

 there, near the free edge of the septa, a short intermediate ridge 

 is intercalated. The largest granulation is on the larger septa near 

 the axial fossa ; and the vertical arrangement is often replaced by 

 an irregular one, or by concentric lines of granules and ridges. 



On the outer septo-costge near the margin of the corallum 

 these lines of ridges and granules run upwards and outwards. 



This ornamentation is found upon the thin septa, and upon all 

 septa between the true synapticula, to which it does not present 

 the slightest resemblance. It is a marked feature when seen 

 from above upon the sides of the septa. 



The septa are with few exceptions, which occur in the rudi- 

 mentary calices, alternately large and small ; and there is much 

 arching over and joining of certain septa within and without 

 larger ones ; and in the greater part of the length of the corallum 

 no septum which reaches the axial space extends to the margin 

 as in Fungia. Usually there are three septo-costse, one within 

 the other, in a line from the axial space to the outer free margin 

 of the corallum. All the septa are whole, and the perforated and 

 immature condition of the thinnest kinds seen in the genus Fungia 

 is not represented in Serpolitha. 



The synapticula, seen from above, are rather close to the free 

 margin of the septa, except in the case of the very large ones ; 

 and their size from within outwards is less than the elongate 

 space which separates them from their neighbours within and 

 without. They are numerous, regular, but wanting here and 

 there ; their obliquity is evident. 



On fracturing a corallum across the length, the synapticula 

 are seen extending from the thick basal wall upwards, in a curved 

 series, on the flanks of the septa. The vertical position is always 

 assumed on certain septa ; but, as a rule, these growths are in 

 gentle curves, extending much higher on the small septa than on 

 the large. A synapticulum may extend without interruption 

 down the whole depth of the interseptal loculus ; but in the 



