35 



Pygidium with an elongated conical, convex axis, 

 with from 12 to 14 distinctly defined articulations, with 

 four narrow pleurae, gradually diminishing in size and 

 bent backwards ; the last pair commencing at about the 

 mid-length of the axis, and extending posteriorly par- 

 allel and close to the axis. The next also nearly par- 

 allel, and the anterior, two pair, with the posterior half 

 of their length parallel or converging. Between each 

 two principal ribs there is a smaller one, slightly ele- 

 vated, and seenis to become obsolete before reaching the 

 fulcrum. The pleurae ai'e at this point bent to the rear 

 at an angle of 90°, and terminating in short spines. 



Surface of the glabella with a few small tubercles ; 

 cheeks coarsely punctate ; pygidium with three or four 

 tubercles on the principal {^leurse. 



Locality and formation : North of Table Bay, Pisto- 

 let Bay, Portland Creek, Newfoundland ; Quebec group. 



If an imaginary circle, with half its diameter equal to 

 the length of the gabella, be drawn with its centre in the 

 middle of the occijiital ring, it will intercept the eyes 

 at their base. A measurement which agrees with An- 

 gelin's figures of Gryplonymus ven-ucosus. 



