254 Prof. T. E. Jones and Mr. J. W. Kirkby on the 



The spines, which occupy the position of the " eye-spot " of 

 other LeperditicBj are stout at the base, of considerable length, 

 and tapering to a fine point ; they are directed outward, upward, 

 and rather forward. In casts from Law Quarry, Ayrshire, 

 kindly sent us by Mr. James Bennie, the spines are about 

 one third of the valve-length. 



This species was discovered by Mr. James Armstrong in 

 the Carboniferous-Limestone series at Ho\^'rat Quarry, East 

 Kilbride, Ayrshire ; it is also found in the same series at 

 Carluke and Brockley, in Lanarkshire, and Craigenglen, 

 Stirlingshire, and in the Scar Limestone near Storr Moss, 

 Lancashire. 



10. Leperditia Bosquetiana, sp. nov. 

 (Plate VII. figs. 2 «, 2 5, 2 c.) 



Suboval in outline ; valves convex, flattened centrally ; 

 dorsal border short and straight ; ventral border elliptical ; 

 extremities regularly rounded ; lateral contour compressed- 

 ovate, rather widest at posterior third, obtusely pointed behind, 

 rounded in front. Length -jV inch. 



This species first became known to us when examining 

 material from Belgium, given to us by our late friend M. J. 

 Bosquet, of Maastricht. It was afterwards found by Mr. 

 James Thomson in Carboniferous Limestone at Tirfergus 

 Glen, Campbelltown, Argyleshire. 



11. Leperditia Youngiana, J. & K. 

 (PI. VII. figs. 3 «, 3 J, 3 c.) 



Leperditia Younffiana, J. & K., MS. 1867, Trans. Geol. Soc. Glasgow, 

 vol. ii. p. 218. 



Subovate, compressed ; dorsal border rather sliort ; ventral 

 border elliptical , posterior extremity regularly rounded ; 

 anterior extremity more pointed than the other and with a 

 well-marked dorsal angle ; valves rimmed, widest near centre ; 

 surface finely punctate. Length oV inch. 



This species, discovered by Mr. John Young, is mainly 

 characterized by the punctate surface of its valves. It occurs 

 abundantly in a bituminous shale of the Carboniferous-Lime- 

 stone series at the Den pit, Dairy, and at a pit at Lugton, 

 Dunlop, both in Ayrshire. 



12. Lejterditia scotoburdigalensis (Hibbert). 

 (PI. VII. figs. 4 rt, 4 h.) 



Cypris scotohurdiyahnsis, Hibbert, 1834, Trans. Koy. Soc. Edinburgh, 

 vol. xiii. p. 179. 



