274 Dr. H. A. Nicholson and Mr. R. Etheridge, Jun., on 



species of Stenopora, Lonsd., are confined to the Carboniferous 

 or Permo-Carboniferous formation of Australia and Tas- 

 mania. There is, indeed, some uncertainty as to the pre- 

 cise geological horizon of some of the deposits which have 

 yielded Stenopora', but there is no reason to think that 

 any of these are of Silurian age, and all the corals of this 

 formation which have been at various times referred to Steno- 

 pora must, pending their complete examination by micro- 

 scopic methods, be placed under Chatetes or Monticulipora. 



Addendum. — The preceding description of the genus Steno- 

 pora was founded entirely upon an examination of 8. ovata, 

 Lonsd., and of the undoubtedly congeneric S. Jackii, nobis. 

 Since this was written, however, we have been enabled to 

 examine 8. tasmaniensis, Lonsd., 8. crinita, Lonsd. ; and a 

 third form, which may be 8. informis, Lonsd., and we have 

 thereby gained some additional information, and at the same 

 time, in some respects, materially augmented the difficulty 

 which we have experienced in our endeavour to interpret the 

 structure of this extraordinary genus. So many points, indeed, 

 have presented themselves for solution, that we think it best 

 to postpone our remarks upon this subject till we can devote 

 a memoir especially to the elucidation of this genus. In the 

 meanwhile, therefore, we will only say here that 8. tasmani- 

 ensis 7 Lonsd., is in all its essential details similar to 8. ovata 

 and S. Jackii, whereas 8. crinita and 8. informis differ in 

 important respects from the species just mentioned, and show 

 a curious approximation to certain of the so-called Monticuli- 

 porai. 



Stenopora ovata, Lonsdale. 



(PI. XIV. figs. 1-1 c ; and woodcut, fig. 2.) 



Stenopora ovata, Lonsdale, in Darwin's Geol. Obs. Vole. Islands, 



p. 163 (1844), and in Strzelecki's Phys. Descr. N. S. Wales, p. 263, 



pi. viii. figs. 3« & 3 b (1845). 

 Chcetetesi?) ovatus, Milne-Edwards & Haime, Pol. Foss. des Terr. 



Pal. p. 273(1851). 

 Monticulipora tumida (pars), De Koninck, Nouv. Rech. Terr. Garb. 



Belgique, p. 143 (1872). 

 Favosites ovata, De Koninck, Pal. Nouv.-Galles dn Snd, pt. iii. p. 156, 



pi. iii. fig. 5 (1877); Etberidge, jun., Cat. Australian Foss. p. 36 



(1878). 



Spec. char. Corallum sublobate or submassive, of cylin- 

 drical or flattened branches, which have a diameter of from 

 half an inch to an inch and a half or more. Corallites vertical, 

 or nearly so, in the centre of the branches, but finally bending 

 outwards nearly at right angles, and being continued for some 

 distance in this direction before reaching the surface. Coral- 



