Palceozoio Corals from Northern Queensland. 223 



Heliolites interstinctus, Linn., has been met with, according 

 to Prof M'Coy*, in the Upper Silurian Limestone of Waratah 

 Bay, Victoria. The researches of Prof, de Koninck have 

 shown the existence of H. megastoma, M'Coy, and II. Murchi- 

 soni in the Upper Silurian rocks (probably Ludlow or Wen- 

 lock) of New South Wales, at Burro wangf, Avhilst the Devo- 

 nian of the same colony has yielded II. porosa, Goldf. \ 



Heliolites porosa, Goldfuss. 



Astraa porosa, Goldfuss, Petr. Germ. 1823, i. p. 61, t. 21. fig. 7. 

 Heliolites porosa, M.-Ed wards and Haime, Polyp, foss. Terr. Pal. 1851, 



p. 218; Mon. Brit. Foss. Corals, 1853, pt. 4, p. 212, t. 47. fig. 1, a-/; 



De Koninck, Foss. Pal. Nouv.-Galles du Sad, 1870, pt. 1, p. 81 ; 



Etheridge, jun,, Cat. Australian Foss. 1878, p. 37. 



Obs. Under this name we have assembled a series of speci- 

 mens from three localities in North Queensland, varying more 

 or less slightly in their characters amongst themselves, but 

 which we think are all referable to Heliolites porosa, Goldf. 

 The composite corallum in these corals is massive, with a 

 flat under surface or base, having few and faintly marked 

 concentric ridges. The calices in all the specimens are cir- 

 cular, pretty equally developed in the same individual, and 

 separated by unequal interspaces occupied by ccenenchymal 

 tubes § ; each calice varies from \—\ of a line in diameter. 

 The tubes of the coenenchyma are rather small and polygonal, 

 and constitute somewhat large interspaces between the coral- 

 lites. The septa are only visible here and there. 



Upon comparing a series of specimens of H. porosa from 

 German and British Devonian rocks we find that considerable 

 variation takes place, — 1st, in the diameter of the corallites 

 themselves ; 2nd, in the size of the ccenenchymal tubuli ; 

 3rd, in the amount of intercalicular space occupied by the 

 latter ; and 4th, in the length of the septa. These variations 

 are, indeed, shown in the figures given by MM. Milne- 

 Edwards and J. Haime. So far as we are able to judge, the 

 Queensland examples appear to occupy a median place in the 

 above scale ; the diameter of the corallites and ccenenchymal 



* As Palceopora, in Progress Report for 187G, no. iv. Geol. Survey 

 Vict., by T. Couchmann, pp. 150, 158 (Melbourne, 8vo, 1877). 



t Foss. Pal. Nouv.-Galles du Sud, 1876, pt, i. pp. 24, 25. 



% Ibid. p. 81. 



§ In this and in the following descriptions of species of Heliolites we use 

 the terms "coenenchyma" and " ccenenchymal tubes" simply iu accordance 

 with previous custom, and for the sake of convenience. There is, of 

 course, no true " coenenchyma " in IIvHolites and its allies ; and the so- 

 called "ccenenchymal tubes" are really a specialized series of small 

 corallites. 



16* 



