﻿H. Efheridge, Jan. — Contributiom to British PalcBontology. 2i3 



but in my former description of P. Soiverbii I noticed a number of 

 fine lines to be seen in the substance of the shell rather than on it, 

 especially when the shell is held at an oblique angle. Through 

 the kindness of Mr. A. Patton I am now able to figure this (Fig. 1). 

 Mr. Meek further remarked on the presence of the v-striae nearly 

 always on one valve only — a character particularly coinciding with 

 our shell, and adds that the v-striee are possibly a "sort of effort 

 at internal markings, of a very different kind, but in some respects 

 analogous to the internal costse of Amussium.''^ 



Genus AvicuLOPEGTEN, M'Coy, 1851. (Annals Nat. Hist., vii. p. 171.) 

 Aviculopecten papijraceus, Sow. Plate XII. Figs. 4 and 5. 



Obs. — I give a figure of one of several specimens well preserved 

 in a dark limestone from the Eaglish Lower Coal-measures. The 

 extreme variation in the ribbing of the same individual is remark- 

 able. The flattened spaces between the primary ribs or ridges are 

 sometimes plain, or subdivided by one large interpolated rib from 

 the margin, which does not reach the beak, or by two smaller ribs 

 which ultimately unite and become one. In the case of the last- 

 named variation, the two interpolated ribs are separated by a less 

 space than separates each of them from its contiguous primary ribs. 

 The specimens before me are all left valves, and have the anterior 

 ear ornamented with from five to six radiating ribs. The posterior 

 margins of all but one specimen are rounded, and form, with the 

 hinge-line, well-marked but obtuse angles. In the exception the 

 posterior margin is slightly sigmoidally curved, and the posterior 

 wing slightly pointed. 



Loc. and Horizon. — Lower Lomax, Bury by Bolton-le-Moor, 

 Lancashire, in a dark limestone of the Lower Coal-measures. Coll. 

 Mas. Pract. Geol., London. 



Genus Anthracomya, Salter, 1861. (Iron Ores of Great Britain ; 

 Mems. Geol. Survey, p. 229.) 



Anihracomya Phillipsii, Williamson. Plate XII. Figs. 6 and 7. 



Unio Phillipsii, Will., 1836 : Phil. Ma^. vol. ix. p. 351. (Without description.) 



Zf/tio linguiformis, Phillips, 18S9 ; Murchison's Silurian System, p. 88. 



Modiola sp., Binney, 1855; Mems. Lit. Phil. Soc. Manchester, 2nd ser., vol. xii. 



p. 221, note. (Without description.) 

 Anihracomya PhilUpsii, Huxley and Etheridge, 1865 ; Cat. Foss. Mus. Pract. Geol. 



pp. 157 and 160. (Without description.) 

 Jones, 1870; Geol. Mag. Vol. VII. p. 217, PL IX. Figs. 



3 and 18. 



Sp. Chars. — Transversely-obliquely-oval, modioliform, elongated 

 in the direction of the diagonal. Anterior end small, its margin 

 rounded ; posterior end much higher than the anterior, with a long 

 obliquely truncated margin, forming by its union with the hinge-line 

 an obtuse angle. Hinge-line straight, almost half the length of the 

 diagonal of the shell ; ventral margin convex, becoming straight 

 anteriorly and passing up obliquely to the anterior end, when, if 

 continued to meet the dorsal mai'giu in a direct line, a very acute 

 angle would be formed. Beaks anterior, almost terminal, very 



