104 CARBONICOLA, ANTHRACOMYA, AND NAIADITES. 



5. Anthracomya lanoeolata, Hind. Plate XV, figs. 11, 11a. 



Modiola lithodomoides (on the autliority of R. Etheridge, sen.), Ward. Trans. 



North Staff. Inst. Min. and Mech. Eng., vol. x, p. 130, 



pi. i, fig. 11, 1890. 

 Anthracomya lanceolata, Hind. Quart. Journ. G-eol. Soc, vol. xlix, p. 267, 



pi. x, figs. 13,13 a, 1893. 



Specific Characters. — Shell very narrrow dorso-ventrally, much elongated 

 transversely. Almond-shaped ; dorsal and ventral margins parallel. The anterior 

 end is much lower than the umbones ; short and convex, its upper border straight, 

 but directed obliquely upwards, rounded below. The inferior border is straight 

 for the anterior fourth of its length, then slightly sinuated, after which it is 

 produced backwards and very slightly downwards, till it curves bluntly upwards, to 

 pass gradually into the posterior border, which is acutely pointed at its centre by 

 a descent of the superior end and rise of the inferior border. The hinge-line is 

 straight, extending about four-fifths of the length of the shell, not raised 

 posteriorly. The umbones are small, only just raised above the hinge-line, not 

 contiguous, situated at a point one-sixth the length of the shell from the anterior 

 end. The lunule is narrow and elongated. The shell is moderately convex in its 

 anterior two-thirds, being gradually flattened above, below, and posteriorly in the 

 hinder third. There is a well-marked constriction, becoming broader and shallower 

 towards the inferior margin, which it indents, in the anterior part of the shell, and 

 an almost obsolete oblique ridge can be traced continuous with the upper border 

 of the umbonal ridge towards the centre of the posterior end. 



Interior. — The surface of the cast is smooth. Anterior adductor scar marginal, 

 large ; posterior scar not apparent. 



/o' rln-ior. — Surface covered with fine lines and flattened laminas of growth 

 which are parallel to the inferior and posterior margin, and therefore sharply 

 angulated or curved behind, before they pass upwards and forwards to terminate 

 in the upper border. 



Measurements. — The type specimen measures — 



Antero-posteriorly . . . .32 mm. 



Dorso-ventrally . . . .10 mm. 



I, ntcrally . . . . .7 mm. 



Locality. — Horizon uncertain. The type specimen was given me by a collier, 

 who stated thai he had picked it up at the Glebe Colliery, Fenton, where a 

 number of seams in the Middle Coal-measures are worked. 



