2 Bolton, New Brachiopoda and Mollusca. 



and in order that they may be of use to geologists who 

 make use of these collections. 



Three of the species here described are from the 

 shales and "bullion-balls" of the Bullion or upper-foot 

 coal-seam of the lower coal-measures. The seam is by 

 far the most remarkable of all the coal-seams which 

 occur in the Lancashire coal-measures, and has yielded 

 to the palaeobotanist and palaeontologist more material, 

 and of greater interest, than all the rest. 



From it were obtained the "coal-balls," by the 

 cutting up of which the late Professor Williamson, your 

 late member Mr. T. Hick, and others were enabled to 

 determine so much of the original structure of the coal 

 vegetation. 



It seems less known that resting upon the roof 

 of the coal are other stone balls, often with an outer 

 crust of pyrites, and usually filled with a great number of 

 Goniatites, Aviculopectens, &c. The shales are full of 

 crushed shells and the bones, teeth, and scales of fishes. 

 Indeed, it is no exaggeration to say that the Bullion 

 seam, and the few feet of shale which form its roof, 

 contain the most varied and abundant fauna of the coal- 

 measures. The species which I describe as Tcllinomya 

 robusta is a middle coal-measure fossil, and appears to 

 be of considerable value as a zonal fossil. In every case 

 where it has been brought before my notice and the 

 locality has been known, it has been obtained from the 

 shales immediately over the Cannel mine. 



DlSCINA (ORBICULOIDEA) ORBICULARIS, Sp. 110V. 



(PI. 5, f. i and 2). 



Discina, G. Wild, "The Lower Coal Measures of 



Lancashire" (Trans. Manch. Gcol. Soc, Vol. XXL, 



1890—92, p. 365, pi. iii., f. 9). 



Diagnosis: Shell almost circular, the sides contracted a 



little posteriorly. Free valve much flattened and slightly 



