93 



The neck segment is well defined and prominent. Cheeks exceedingly 

 convex, most elevated along the middle or along a line half way between 

 the glabella and the margin. The neck furrow extends all across the 

 cheeks at the posterior margin. 



Pygidium semi-oval, narrowly rounded behind, very convex, about as 

 wide as the head, but one-third longer ; axis acutely conical, strongly 

 convex about three-fourths the whole length and a little less than one-third 

 of the whole width, well defined all round by the dorsal furrows. The 

 axis is divided into six segments, the anterior of which is subdivided by a 

 small furrow which runs across it and extends into the anterior segment of 

 the side-lobes. In the side-lobes there are five segments, the last one 

 sometimes obscurely defined : these do not extend quite to the margin. 



Surface of both head and pygidium covered with small granular tuber- 

 cles, more distinctly developed in some individuals than in others. Some 

 specimens of the pygidium have a space all round the margin smooth. 



Length of head about 1 line ; width about If lines. Length of 

 pygidium 1 lines. These measurements refer to the largest specimens 

 seen. In many the proportional length and width differ a little from the 

 above. 



The pygidium and head have never been seen in connection, but several 

 of each occur together in the same small specimen of stone, and it seems 

 therefore almost certain that they belong to each other. 



Locality and Formation. Point LeVis. In the thin-bedded limestone 

 interstratified in the graptolitic slates, Quebec group. 



Collector. J. Richardson. 



Genus ENDYMION. (N. gen.) 



Generic Characters. In the only species of this genus at present 

 known, the head is semi-oval and convex ; glabella ovate, convex, with a 

 large elongate, oval tubercle on each side. The facial suture appears to 

 terminate at the posterior angle or just outside of it, and running forward 

 to cut the anterior margin on a line passing through the middle of the 

 cheek, parallel with the longitudinal axis of the body. On this point, 

 however, there is yet some doubt, as the moveable cheek has not been 

 seen, and what appears to be the facial suture may be a fracture. Thorax 

 distinctly trilobed ; axis convex ; side-lobes flat ; six or seven segments ; 

 the pleurae with a well-defined groove crossing them diagonally outwards 

 and downwards. Pygidium semi-oval, distinctly trilobed, with the axis 

 and side-lobes divided into segments by well defined furrows. 



