MOUNTAIN LIMESTONE FOSSILS. 205 



to Mr. John Ruthven of Kendal, the well-known enthusiastic col- 

 lector of palaeozoic fossils. 



Rare in the impure carboniferous limestone of Dent, and one 

 small specimen from the similar limestone of Lowick, Northum- 

 berland. 



{Col. University of Cambridge.) 



Sanguinolites clava (M^Coy). 



Sp. Char. Elongate, claviform, three times longer than wide, 

 anterior end large, obtusely rounded, dorsal and ventral mar- 

 gin with a slight upward curvature, no byssal furrow ; poste- 

 rior end slightly narrowed, subtruncate, rounded ; beaks large, 

 obtuse, a broad ovate striated lunette beneath them on the 

 anterior side; posterior lunette, the largest of the hinge-line, 

 wide, hollow, bounded by the obtuse ridges of the dorsal mar- 

 gins ; valves very convex in front, their depth beneath the 

 beaks five-sixths of the width from them to the ventral margin, 

 gradually becoming more compressed towards the posterior 

 end, where the depth is only half the width ; posterior slope 

 gently convex, undefined, diagonal ridge not marked ; surface 

 covered with thick, rugged, subequal ridges, arising a little 

 behind the anterior lunette, and slightly thickening towards 

 the posterior slope, which is defined by their termination, and 

 only marked by fine striae of growth parallel with the end ; 

 anterior lunette and a small portion of the anterior extremity 

 also nearly smooth ; the ridges, where the outer surface is pre- 

 served, are covered with a minute irregular striation approxi- 

 mately parallel with the margin. Length from anterior to 

 posterior end about 5 inches 2 lines, width from beak to oppo- 

 site ventral margin 1 inch 1 1 lines, depth of both valves 1 inch 

 9 or 10 lines. 



This fine species is remarkable for the clavate form produced 

 by the gibbosity of the valves near the anterior end and the 

 tapering towards the posterior extremity. Of the internal im- 

 pressions I have only seen the anterior adductor, which is broad, 

 rounded, and shallow. The only approximation to this species 

 published that I know is an imperfect fragment of one end of a 

 shell called S. maxima by Portlock, Geol. Rep. t. 36. f. 1, which 

 is flatter with smaller beaks, a more truncate anterior end, &c. 



Not uncommon in the carboniferous limestone near Llangollen, 

 North Wales. 



{Col. University of Cambridge.) 



Sanguinolites subcarinafus (M^Coy) . 

 Sp. Char. Elongate oblong, tumid; beaks very large, obtuse, 



