Manchester Memoirs, Vol. xli. (1897), No. 0. 5 



A small slab in the Dugdale collection bears two 

 whole shells with open valves. 



A small slab with a single pair of valves is in the 

 Cairns collection at the Manchester Museum. 



This species has a general resemblance to A . pumila 

 and A . minima var. carinata, but differs from the former in 

 being much narrower in proportion to the length, in the 

 more forward position of the umbo and the produced 

 anterior extremity. The latter feature also distinguishes 

 it from A . minima var. carinata, as also the absence of a 

 strong oblique ridge. 



The species occurs much lower than any other of the 

 genus in the English carboniferous. 



Tellinomya robusta, sp. nov. (PI. 5, f. 6, 7, 8 and 8a). 

 Diagnosis : Shell oval, obtuse, surface smooth, marked 

 by faint concentric lines of growth, strongest along 

 anterior border. Valves strongly convex, umbones 

 gibbous. External ligament present and usually well 

 defined. Anterior lunule well marked, and a posterior 

 escutcheon which is bounded by a slight ridge passing 

 backwards from the umbones to the upper posterior 

 border. Anterior border a little produced and well 

 rounded, and gradually merging into the ventral border. 

 Posterior border short, sometimes a little produced and 

 angulated. 



Localities and Horizons : 



Chequerbent, 



Tyldesley, 



Bank Colliery, L. Hulton, 



Worsley Tunnel, 



Watergate, Bolton. 



Cannel mine 



of the 



middle coal-measures. 



Hulton Park, Bolton, 



Mill Hill Bleachworks, Bolton ; horizon not known. 



Observations : This species is readily distinguishable by 



its stout swollen form and smooth surface, together with 



