142 PEOF. p. M. DTJIfCAN ON THE 



position, large septa are seen radiating from the axial space to the 

 circumference, and between them are medium-sized ones and also 

 some very thin and extremely delicate-looking septa. The inter- 

 loculi are the spaces between tlie septa, and which in true corals are 

 occupied by mesenteric folds during life, and they are now seen to 

 be empty for some little distance from the axial space and also in 

 their upper portions. Lower down, however, and on a level with 

 the top of the thin intermediate septum is (in every interseptal 

 loculus) a series of structures which join the sides of approximate 

 septa together. As each septum, of whatever size it may be, 

 has a row of these synapticula along its sides from within 

 outwards (from axial space to circumference), a very peculiar 

 appearance is given to the coral, and one which has been correctly 

 drawn by Pourtales and Klunzinger*. Each synapticulum is 

 stout, broad from side to side, nipped in and short from within 

 outwards. There are about eight or nine of them, with spaces 

 separating them, elliptical in outline, in a centimetre. What 

 is seen are the tops of the synapticula. 



These cross growths are solid-looking, and they are nearly 

 subequal, so that a very thin and leaf-like septum has great 

 joining-structures on its sides, which are as large as those which 

 are seen on the flanks of great primary septa. Yery often the 

 synapticula are attached to a large septum and only partly so to 

 a very thin septum, a portion of some synapticula remaining 

 free. 



Besides these large synapticula, a very few smaller ones are 

 seen, wHcli may or may not reach across the interseptal space 

 from one septum to its neighbour. 



Moreover, where the very delicate septa overlap those between 

 them their tissue is finely trabeculate. 



The ornamentation of the sides of the septa is of small gra- 

 nules, wbich increase, in the form chosen as the example, in size 

 towards the axial space of the coral ; but the synapticula and the 

 more or less imperfect growths just alluded to are independent of 

 and are not modified granular ornamentation. Not a trace of 

 dissepimental tissue stretching across the interseptal spaces and 

 closing them is to be seen, and it does not exist in the Fungidae 

 proper. 



When a specimen is carefully fractured across, at right angles 



* The synaptieular series are not visible from above near tlie axial fossa, but 

 become so further out. 



