139 



Surface with fine rounded strioe four or five in one line and also with 

 obscure concentric wrinkles, not always seen on the casts. 



Length of large specimens about two inches ; height eight or nine lines. 

 Individuals of all sizes from nine lines in length upwards occur. 



The position of the beaks varies, from one-fifth to three-eighths the 

 length from the anterior extremity. The posterior part of the shell is 

 often more narrowed and pointed, from the beaks backwards, than it is 

 in the specimen figured ; sometimes more obtuse and uniformly rounded. 



Locality and Formation. — Arisaig, Nova Scotia. Upper Silurian. 

 Collector.— T. C Weston. 



Grammysia remota, (N. sp.) 



Plate 9, tig. 2. 



Description. — Sub-ovate or sub-triangular, the height nearly equal to 

 the length ; beaks a little in front of the mid-length. The whole of the 

 margin of the lower half of the shell is broadly rounded, or depressed 

 semicircular. The anterior extremity is most prominent at about the 

 mid-height ; above which point, it is gently convex, or nearly straight in 

 outline, and sloping towards the beaks ; below the mid-height it gradually 

 curves into the ventral margin. The hinge line and dorsal margin slope 

 downwards nearly to the mid-height of the shell, nearly straight or slightly 

 concave. A lunette extends from between the beaks about two-thirds the 

 length of the dorsal margin. 



Surface with rather strong concentric wrinkles from half to one fine 

 wide, covered with very fine concentric strise. 



Length of the only specimen collected, twenty-six lines ; height from 

 the ventral -margin to the beaks, twenty-two lines ; depth of both valves, 

 nine lines. 



The specimen is somewhat distorted and compressed laterally. When 

 perfect the depth of both valves was probably twelve lines. 



From the beak of the right valve, a shallow groove extends, almost 

 vertically to the lower third. 



Grammysia rustica (N. sp.) 



Plate 9, fig. 3. 



Description. — Shell transversely elongate-ovate ; length nearly twice 

 the height ; anterior extremity the largest ; beaks at about the anterior 

 third of the length ; ventral margin moderately and uniformly convex ; 

 dorsal margin nearly straight ; sloping downwards from the umboncs. 



