OF NEW SOUTH WALES. 81 



K 



shallow, and long ; the columella projects from the bottom of it 

 as a distinct straight lamella, stout in the body of the coral and 

 thinner at its free edge, is essential and marked by distinct 

 papillse at the junction of the septa ; septa delicate, highly gran- 

 ular, and often wavy at the inner margin ; minor axis of calice 

 higher than the longer ; costee faintly marked, or distant and 

 linear ; epitheca in strong curved folds or in festoons between 

 the costse. Height from 20 to 25, length of calice 8 to 10, width 

 6 to 8 millim. Fossil only ; common at Muddy Creek. Found at 

 Mount Gambier, but as a cast only. Very common and large at 

 Table Cape, Tasmania. 



Placotrochus deltoideus, Duncan. 



Coral deltoid, finely pedicellate, compressed ; calice wide and 

 long ; costas somewhat distinct ; epitheca strong in arched ridges ; 

 columella long, sharp, thin, and faintly papillate ; septa not 

 exsert, feebly arched, delicate, granular, with flexuous inner 

 margin, in six systems of five incomplete cycles ; angle of sides 

 about 60°. Alt. varying from 30 to 40 mil. ; maj. axis little less 

 than height, and minor about one-third. Very common as a 

 fossil at Table Cape, Tasmania ; less common at Muddy Creek, 

 and River Grellibrand, Victoria, where it is also smaller. 



Placotrochus elegans. Nobis. See Proc. Roy. Soc. N. S. W., 



1877. 

 A very small species with coronate edge . 



Family Oculinid^, Edw. & -ET., 1849. 



Corallum compound, dendroid, growing by lateral buds, ccenen- 

 chyma highly developed and very compact, on which the costae 

 are represented by striae or granulations ; visceral chamber with 

 few traverses but gradually filling up from below ; septa few, 

 well developed, imperforate, and without synapticula. 



This family for the most part includes living species, but there 

 are a few tertiary and secondary forms, though none older than 

 the Oolite. There are very few Australian species. 





