534 E. Wethered — Organisms in Carboniferous Limestone. 



are also given, one of which, too, is doubtful. In each case we 

 get five undoubted genera and species, and of these four appear 

 in both lists. Mr. Kirkby writing to me remarks : " It is surprising 

 how similar the groups of species are to those we have just described 

 from the Gayton boring." 



Professor Jones, after an examination of different samples from 

 the same locality, makes similar remarks. Of the forms described 

 from the Gayton boring three have not been known to occur above 

 the Calciferous series of Scotland, which horizon is immediately 

 above the Old Eed Sandstone (Devonian). The forms referred to 

 are B. sublunata, C. extuberata, and G. attenuata. Of these two 

 appear in my list. 



Crinoidea. — The Crinoidal remains in the Lower Limestone Shales 

 appear to be those of two genera. One of these is Poteriocrinus crassus, 

 Miller, and the other probably Miller's genus Rhodocrinus. In some 

 of my slides apparent pentagonal joints are seen (PL XIV. Fig 2), 

 which I was at first puzzled to account for. On reference to Miller's 

 " Crinoidea," I found that he had figured ' joints resembling mine, 

 which were also collected in the Forest of Dean, and that he referred 

 them to Rhodocrinus verus. Miller in his "Description" ex- 

 presses some doubt as to whether all the forms referred by him 

 to this genus are really the same species ; he remarks : " In the 

 columns (pi. ii. fig. 1, t. 22) which I consider as belonging to the 

 animal of this genus, I have noticed two different modes of organiza- 

 tion, which inclines me to suspect that although I am only able to 

 treat of one species as decidedly ascertained, yet two distinct species 

 may really exist. Thus in regard to the surface of adhesion, some 

 columnar joints display numerous radiating stria? proceeding imme- 

 diately from the alimentary canal to the circumference (figs. 6 to 10); 

 other joints (figs. 1 to 5) have only a narrow striated rim with a 

 smooth central area ; and again some columns (figs. 11 to 15) are 

 formed of joints of uniform thickness, from some of which, occa- 

 sionally, several side-arms proceed; whilst other columns, particularly 

 those from Mitcheldean, are formed of joints alternately thicker and 

 thinner, smaller and larger, much contracted at their margin of mutual 

 adhesion. In these every second or fourth joint is considerably 

 thicker, showing at its circumference five or six tubercles, which 

 render it angular and its surface waved, to which the joints above 

 and below conform." It is therefore clear that Miller detected some 

 points of difference in the specimens from the Forest of Dean compared 

 with those from other localities. With regard to the stries, I think 

 he attaches too much importance to them ; they are simply striations 

 on the articular faces of the stem-joints, and the features pointed out 

 by Miller are due to the particular portion preserved or examined. 

 With regard to the joints themselves, these are features which are of 

 importance, and though Miller only considered them of sufficient 

 note to possibly justify a different species, it is probable that further 

 investigation may prove that the fossil is wrongly referred to the 

 genus Rhodocrinus. Having doubts regarding the specimens which 

 I had collected, I sent them to Dr. P. Herbert Carpenter, F.R.S., and 

 1 " Miller's Crinoidea," 1821, Mhodocrinites, plate 2, figs. 17, 18, 19, p. 107. 



