CONTRIBUTIONS TO PALiEONTOLOGY. 175 



GENUS CHARIOCEPHALUS (n.g.). 



[Gr.jap^f, gratia; Kecpa/.T]^ caput.} 



Head broad ; cheeks moderately convex towards the eyes ; gla- 

 bella regularly convex, and marked by transverse furrows ; 

 eyes large ; facial suture cutting the contour of the front at or 

 near the centre. Thorax unknown. P^-gidium ? 



CHARIOCEPHALUS WHITFIELDI ( n. s.). 



PLATE VI, FIGS. 4?— 51;^ AND PLATE X, FIG. 20. 



Head wide^ with gently convex cheeks. 



Glabella regularly convex, the sides rising rather abruptly from 

 the depression, semielliptical, rarely appearing a little truncate 

 in the front, and in the cast of the interior entirely smooth, or 

 faintly marked by two pairs of furrows, the posterior one of 

 which has rarely been seen to extend across the middle. Occipi- 

 tal furrow shallow, gently depressed : occipital ring depressed- 

 convex. Dorsal furrow rather broad and w^ell defined, contined 

 in front of the glabella in nearly the same strength as at the 

 sides ; and just within the contour of the fronts it is marked 

 by two minute rounded pits. 



The facial suture cuts the contour of the head at or near the 

 mriddle of the front, and, making a gentle convex curve, it ap- 

 proaches the glabella just anterior to the eye-lobe, and following 

 the curve of the latter to its posterior limit, continues in a 

 gently diverging line to the base of the cheek halfway between 

 the dorsal furrow and the outer margin. 



EiXED cheeks narrow, suddenly contracted in front of the eye, 

 and gently expanded towards the palpebral lobe, and extended 

 in a comparatively short posterior limb. The frontal limb is 

 narrow, convex, sublunate or sometimes sublinear and straight. 



Movable cheeks with a regular circular curve from the front to 

 the beginning of the spine at the posterior angle : the lower 

 part of the cheek is wide, gradually narrowing anteriorly, with 

 the border reaching to the centre of the front of the head. The 

 inner angle shows a large ocular sinus. The posterior limb is 

 extended into a straight diverging spine. The surface is gently 

 convex towards the eye, gradually depressed to a broad shallow 

 groove, which leaves a thickened border of the same width. 



