52 Prof. P. Martin Duncan — On Cretaceous Madreporaria. 



Northern Wyoming. From the Wind Eiver Valley Mr. Wortman 

 brought two specimens, and ten from the Big-Horn Basin." (op. cit. 

 pp. 462-463). 



Note. — We are indebted to the kindness of Prof. B. D. Cope for 

 permission to reproduce the figure of Phenacodus given in our PI. II. 

 — Edit. Geol. Mag. 



II. — An Answer to " Observations on Some Imperfectly Known 

 Madreporaria from the Cretaceous Formation of England, 

 by K. F. Tomes, Esq., F.G.S." 



By Prof. P. Martin Duncan, F.R.S. 



I HEARD this communication read at the Geological Society in 

 June last, and I made some remarks upon it which are noticed 

 in the Proceedings of the Society. A considerable portion of the 

 paper consisted of criticisms of some of my work which appeared 

 in the British Fossil Corals (2 ser. Pal. Soc. part ii. Nos. 1 and 2, 

 1869-70). Some specimens were exhibited, in the author's absence, 

 which were presumed to afford evidence of a satisfactory kind. But 

 it was observed that the very imperfect and bad condition of the 

 fossils did not substantiate the author's statements. Many specimens 

 which ought to have been exhibited were not before the Society, and 

 yet the classificatory position of some very rare corals could then 

 and there have been settled. As this paper was not published by 

 the Geological Society, as the author ignores the remarks I made on 

 the paper, and as it appears in the Geological Magazine for 

 December, 1885, p. 541, I ask a small space for a reply. 



In answer to Mr. Tomes, I assert that Micrabacia Fittoni, nobis 

 (Pal. Soc. loc. cit. p. 37, pi. xiv. figs. 6, 7, 8, 9), is not a variety of 

 Cyclocyathus Fittoni, Edw. and Haime (Pal. Soc. Brit. Foss. Corals, 

 pt. i. p. 63, pi. xi. figs. 3, 3a, 3b, 1850). Neither is it that species. 

 The species of M. Fittoni was founded upon a solitary yet good 

 specimen, and the drawings of it were good and from nature. Some 

 years after the description of the species, I investigated the mor- 

 phology of Micrabacia coronula, and the results were published 

 (Quart. Journ. Geol. Soc. vol. xl. 1884, p. 561 ). 1 I pointed out that 

 there was reason to doubt whether M. Fittoni was a true Micrabacia ; 

 but that as the type was not accessible, I did not feel disposed to 

 remove the form until I had an opportunity of investigating it anew. 

 It was, however, not necessary to place the form out of the Fungida, 

 to which section it belongs. I should have been glad to have seen 

 another specimen, but Mr. Tomes did not give me the opportunity, 

 and I am aware that he has not the type. So it is now necessary to 

 compare the form I described with the species with which it is 

 attempted to be associated, namely, Cyclocyathus Fittoni. 



Amongst the structural details of Cyclocyathus Fittoni, Edw. and 



Haime, is a thin epitheca, and the costse of the first and second 



cycles are more prominent than the others ; these details are not seen 



in M. Fittoni. The upper or calicular surface is rather convex 



1 Omitted be to noted by Mr. Tomes. 



