328 TABULATE CORALS. 



which divide the entire mass into a series of superposed strata. 

 Calices subpolygonal. No traces of septa." 



Not having seen the original specimens upon which Milne- 

 Edwards and Haime founded the genus Dania, I am unable to 

 give any final opinion as to the validity or the reverse of the 

 genus. It is clear from their description, and still more from 

 their figures, that Dania Huronica is a Chaetetoid or Monti- 

 culiporoid Coral ; and it is also clear that the single character 

 emphasised by Milne-Edwards and Haime namely, the pres- 

 ence of tabulae placed at corresponding levels in contiguous 

 tubes is not of itself sufficient for generic characterisation. 

 This is amply proved by the fact that a like periodic production 

 of tabulse, giving rise to a similar division of the corallum into 

 superimposed concentric layers, occurs in such different forms 

 as Stenopora crinita, Lonsd., from the Carboniferous, and 

 Monticulipora undulata, Nich., from the Lower Silurian, as 

 well as in the familiar Chcetetes radians, Fischer, of the Car- 

 boniferous. Professor Martin Duncan (Third Rep. on the 

 Brit. Foss. Cor.; Rep. Brit. Ass. 1871, p. 128) is of opinion 

 that Dania, E. and H., is inseparable from Chcetetes, Fischer, 

 and in this view he is very probably correct, though I do not 

 know what positive evidence exists upon the point. 



The only other coral that I am acquainted with as having 

 been referred to the genus Dania is the Thecia multiseptosa, 

 A. Romer (Beitrage III., p. 2, PI. 2, f. i, 1855), from the 

 Lower Devonian of Germany- This form was doubtfully 

 referred by Romer to Thecia, but Giebel assigned it to Dania 

 (Sil. Fauna Unterharz, p. 59, PI. 6, f. 3 and 4, 1858), and this 

 view is also taken by Kayser (Fauna d. Alt. Devon. Ablager. 

 des Harzes, p. 223, 1878). Judging from the figures given by 

 Kayser, the close-set tabulae are certainly placed at correspond- 

 ing levels in contiguous corallites ; but there is nothing definite 

 brought forward except this character to justify its being placed 

 in Dania. It appears to be either a member of the genus Chce- 

 tetes or Favosites. 



