8 CARBONICOLA, ANTHRACOMYA, AND NAIADITES. 



The same writer is responsible for the following statement in his Appendix to 

 the ' Geol. Survey Memoir, Country round Wigan,' 2nd edition, 1862, p. 43 : — 

 " With Goniatites, Anthracosia occurs in abundance, not actually discovered in the 

 same layers, but closely intermixed, so that it is difficult to believe that one is a 

 fresh- and the other a salt-water shell." No other observer has made a similar 

 statement ; but he goes on to say, " Anthracosia acuta occurs in strata undoubtedly 

 marine at Clitheroe ; " and names the discoverer — a statement which is very vague 

 as regards locality and horizon ; and, as the specimen itself is not in evidence, it 

 is impossible to place much reliance on this solitary find, which was probably 

 another bivalve from the Carboniferous or Yoredale beds. 



There are at least two beds in Scotland in which Carbonicola (Anthracosia) and 

 undoubted marine fossils appear to occur together ; one of these is the " Slaty- 

 band " or " Lingula-iron stone " of Lanarkshire, which contains — 



Anthracosia (Carbonicola) aquilina. 

 ,, acuta. 



Lingula mytiloides. 



„ squamiformis. 

 Anthracosia (Carbonicola) subconstricta. 



(' Mem. Geol. Survey Scotland,' Explanation of Sheet 23, pp. 89, 90, 1873.) 



This bed is probably equivalent to the Gannister Series in England, and belongs 

 to stage E. 



The other bed is that at the base of the " Cement-stone Group " at Water of 

 Leith, from which Dr. Rhind * and Captain T. Brown 2 have obtained a shell, 

 according to the former, " from a bed of shale below ten feet of sandstone, but the 

 marine character of the bed is not made out, and it is very probable from the 

 plant remains in the Cement-stone Group that these beds are not marine. 

 R. Etheridge, jun., 3 records a similar shell (the original having been lost, the 

 reference is somewhat doubtful) from hardened shale in a quarry on the north side 

 of the Colinton Road, under Craiglockart Hill, near Edinburgh, at about the same 

 horizon. 



It has generally been considered that Anthracoptera crassa (the Myalina crassa 

 of Fleming, Etheridge, and others), which I have shown to be anatomically 

 identical with the Naiadites (Anthracoptera) of the Coal-measures, 4 is a marine shell. 

 It occurs at Cults, Pitlessie, Fife, in a bed almost completely composed of these 

 shells, at the west end of the workings, now almost covered with talus ; but there 

 are several broken specimens lying about with corals (Zaphrentis), Aviculopecten, 

 fish remains (Megalichthys) and Stigmaria — a curious fauna, indicating the 



1 Rhind, ' Age of the Earth,' p. 167, pi. ii, figs, a, b. 



2 'Ann. and Mag. Nat. Hist.,' ser. 1, vol. xii, pi. xvi, fig. 1, p. 394 ; 'Fossil Conchology,' p. 178, 

 pi. lxxiii, fig. 8. 



8 ' Quart. Journ. Geol. Soc. Lond.,' vol. xxxiv, pi. ii, fig. 20, p. 16, 1878. 

 4 Hind, • Geol. Mag.,' Decade III, vol. x, Nov., 1893, p. 514. 



