SE^ . 1901 



LINGVLA ASSOCIATED with LEPIDODENDEON. 

 By R. Etheridge, Junr., Curator. 



The Rev. J. M. Curran recently presented to the Trustees some 

 interesting specimens of a Lingula, associated with Lepidodendron, 

 discovered by him near Orange, in beds that he believes to be of 

 Upper Devonian age. 



The remains of this Lingula are pressed and matted together 

 in enormous numbers, forming a bed of some thickness, and 

 extending over a considerable area, so forming an excellent horizon 

 for geological work in the district in question. 



The type is that of Lingula mytiloides, Sby., of the Carbon- 

 iferous Period, and might pass for a large variety of it. One 

 valve has been sufficiently exposed from the matrix to afford the 

 following details. Like those of L. mytiloides the convexity of 

 the valves is lessened along the middle line longitudinally, widen- 

 ing as the surface so formed extends towards the front, the 

 sharper declivities of the lateral portions giving rise to apparent 

 angularities at the junction of the central and lateral surfaces, 

 and assuming the appearance of radii. This feature in L. myti- 

 loides is only partially shown in Davidson's figures of the latter,' 

 but better in those of L. credneri, Geinitz," also a Carboniferous 

 form, and is still more apparent in one of Phillips' figures of L. 

 ynytiloides.^ It is also seen in L. punctata, Hall,^ of the Hamilton 

 Group, in North America, and again in L. cuyahoga, Hall,'^ 

 although not to the same extent. 



Only one Palpeozoic Lingula has so far been described from our 

 rocks, L. ovata, Dana," from the Upper Marine Series of Black 

 Head, Illawarra, but this is of an entirely different type. 



It will be seen from the foregoing remarks that the combination 

 of characters yielded by this Lingula point either to a Devonian 

 or Carboniferous facies, or to be more precise either of Upper 

 Devonian or Lower Carboniferous age. 



1 Davidson— Mon. Brit. Foss. Brach., ii., Perm, and Garb. Species, pt. 5 

 (4), 1861, pi. 48, figs. 29-30. 



2 Ihid, figs. 38-40. 



3 Phillips— Geol. Yorksh., pt. ii., 1836, pi. xi., fig. 17. 



4 Hall— Pal. N. York, iv., pt. 1, 1867, pi. i., fig. Qa-g. 



5 Ibid, pi. i., fig. 5. 



