118 



Contributions to Palaeontology. 



in front of the occipital furrow as the width ; sides pa- 

 rallel; front rounded. Occipital furrow comparatively 

 narrow and well defined, with a wide, nearly flat or little 

 convex occipital ring. The posterior glabellar furrow 

 crosses the glabella as far from the occipital furrow in 

 the middle as the width of the occipital ring, and curves 

 forward so as to terminate a little behind the anterior 

 limit of the palpebral lobe. Anterior to this furrow 

 there is on each side a shallow groove, reaching about 

 one-third across the glabella. 



The facial suture cuts the anterior contour in a nearly ver- 

 tical line from the outer limb of the palpebral lobe, and 

 is thence directed inwardly in a slightly curved line to 

 the anterior limit of the palpebral lobe ; thence turning 

 almost rectangularly outwards, it curves gently down- 

 wards into the posterior limb of the cheek, at a distance 

 from the dorsal furrow of five-sixths the width of the 

 glabella. Dorsal furrow strongly defined at the sides, 

 and distinctly limiting the glabella in front. 



Fixed cheeks comparatively narrow, spreading opposite 

 the centre of the palpebral lobe ; the posterior limb 

 about the same width as the cheek anterior to the eye, 

 and deeply grooved; the frontal limb broad and nearly 

 flat, without elevated or thickened border, or with this 

 feature scarcely perceptible. The extension of the fron- 

 tal limb is equal to a little more or less than half the 

 width of the glabella. 



Movable cheeks large, somewhat triangular, with a deep 

 sinus at the inner angle for the place of the eye, convex 

 towards the eye, and flattened or concave between this 

 convexity and the outer margin : exterior limb scarcely 

 thickened, produced posteriorly into a thin flattened 

 spiniform process. 



Hypostoma broad; the body convex and subcircular or 

 very broadly oval, with margins expanded and furrowed 

 near their antero-lateral angles. 



