50 K?:coi;i)s ok ihf. austkalian muiseum. 



II. — A Species of Coluiinidria v\icn\ ihe New Souih Wales Devomax. 



The corallnm iu this coral is, in accordance with the more tvpical 

 sti'Tictiire of Colam.naria, composite and massive, iu this instance boliti- 

 form in shape, measuring six and a half inches by five. The straight 

 prismatic polygonal corallites, tirraly xinited to one another laterally have 

 an average diameter of 3 mm., sometimes increasing to 4 mm. The 

 corallite walls are well developed, unthickened with stereoplasma, and 

 the primordial walls constantly visible in the structural sclereuchyma. 



The septa aie plain and non-denticulate, primary and secondary, but 

 irregular iu development. The normal number appears to be twenty, 

 the average fifteen inclusive, whilst twelve is not an uncommon number. 

 The full number of twenty is much less than that seen in the type species, 

 C alveohitd, in which there are from twelve to fifteen in both series, 

 primary and secondary. 



The irregularity in the septal development is remarkable. The 

 primary septa (1) may, or may not, reach the calicinal centre; (2) are 

 rarely straight, but usually more or less curved ; (3) two or three contig- 

 uous lamellae may unite near the centre, or at half the distance between 

 the latter and the corallite wall and there stop short, thus forming 

 fasciculate bundles more or less ; (4) those that arrive at the calicinal 

 centre appear to become confused with one another, hardly an inter- 

 mingling, and cei-tainly no i^evolution ; (5) exceptionally several may 

 unite at the centre, as many as six have been counted, but there is no 

 appearance whatever of a St. George cross as in the genus Sfduria. The 

 secondaiy septa (1) may be about half the length of contiguous primaries ; 

 (2) reduced to mere tooth-like pi'ojections ; (3) often not developed at 

 all between any two primaries ; (4) two instead of one may occupy such 

 « position. 



This union of two or three primary septa at or near the calicinal 

 centre certainly occurs in the type species C. alveohitd, Goldfuss,^ and 

 again in 0. cdliciuK, Nicholson,^ but extreme irregularity, as described 

 above, is not seen in any illustrations I have access to. 



Altliough the primcn-dial corallite walls are preserved tliose of the 

 septa are not so. Thei-e is no ti'ace whatever of dissepimental tissue 

 within the interseptal loculi. 



When examined in longitudinal section, the lamellar nature of the 

 septa is at once made apparent. The tabulae are complete and horizontal, 

 but slightly deflected at the extreme pei-ipheries, and on same plane iu 

 contiguous corallites ; neither convex noi" concave flc)ors were obsei'ved. 



The structure of this cox-al is obviously that of < 'nl inmntrin, as 

 depicted by Nicholson, and following him, by Ijambe. The only valid 

 difference I can see is the often actual extension of the septa to the centres 

 of the visceral chambers, the confusion I pi-eviously mentioned being 

 perhaps due to stress, of which evidence is certainly present. It is pro- 

 posed to call it Coliiuinaria tieiiiiniiheusis. 



1 Nicholsdii— Tall, ('..rals I'al I'.-ri...!. JSTit, j.l. x., H^'. 2. 



-' l,aiiilie— <"«iiitril>. Caiiailiaii I'al . ii.. pt. ii., I'.tOO, ])1. vi., ti^. I. 



