136 



eight in one line, as seen on the anterior extremity. These are separated at 

 intervals of from half to one line, by obscure grooves. At the carina the^ 

 striae are coarser, three or four in one line. There are no radiating strige. 



Length of largest specimen collected about two inches. Height of the 

 side below the umbonial ridge, eleven lines. The height of the shell, when 

 placed in the usual position, would be somewhat less than eleven lines. 



This may be the species cited as Cr. cymbceformis (Sow. ) in the Rev. 

 D. Honeyman's paper " On the Geology of Arisaig, Nova Scotia, (Jour. 

 Geo. Soc, vol. 20, p. 344.) It is certainly closely related thereto but 

 still appears to be distinct. The figure in the " Silurian system," plate 

 5, fig. 6, shows the beaks extending beyond the anterior extremity. 

 Again, Prof. McCoy (Pal. Foss, p. 275) says, " anterior side very small, 

 scarcely extending as far as the beak.'' In one species the anterior 

 extremity extends a little beyond the beak. It has also the edge of the 

 carina obtuse and even slightly grooved. 



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

 Collector,— 11. C. Weston. 



GONIOPHORA BELLULA. (N. Sp.) 



Plate 8, fig. 9. 



Description, — Shell trapezoidal, moderately convex; length not quite 

 twice the height ; dorsal and ventral margins sub-parallel ; anterior end 

 projecting a little beyond the beaks ; posterior extremity abruptly trun- 

 cated, nearly straight, gently convex, forming an angle of about 90^ with 

 the ventral margin ; curving forwards, upwards and joining the line at an 

 angle of about 11 0\ Ventral margin nearly straight, all except the ante- 

 rior fifth which is curved upwards. The beaks seem to be at about two- 

 thirds the height of the shell, and a little behind the most projecting 

 anterior point. The angulation is moderately developed, rounded when 

 a little w^orn, when perfect with a sharp elevated rib-like edge. 



The sides of the shell below the carina flattened or gently concave, 

 from near the front backwards ; from the beaks downwards moderately 

 convex. Above the carina, with a flat or gently concave slope. 



Surface with five or six transverse striae, in a width of two lines. These 

 are crossed in the middle two-thirds by more distinct radiating striae, six 

 to eight in two lines. A small portion of the anterior extremity with only, 

 the transverse lines. Above the carina the striae are finer, the surface 

 when not magnified appearing nearly smooth. 



Length of the specimen figured fourteen lines ; height at the umbones^ 

 eight lines. 



