152 



Contributions to Palaeontology. 



straight, sometimes a little curved ; sides nearly straight 

 and regularly converging: the posterior glabellar furrow 

 oblique, and faintly marked ; the middle one less dis- 

 tinct; the anterior one sometimes obscurely indicated 

 near the anterior extremity of the glabella. Occipital 

 furrow strongly impressed at the sides, but often faintly 

 marked or scarcely perceptible in the middle. Oc- 

 cipital ring narrow at the sides, wider and inclining 

 backwards in the middle, and rising to the base of a 

 strong elevated spine, which is directed obliquely back- 

 wards, and in the course of its length is gently curved. 

 Dorsal furrow well denned, not deep, a little more 

 strongly impressed at the anterior angles of the glabella, 

 and continued in front of the same strength as at the 

 sides. 



Facial suture curving slightly outwards from the frontal 

 margin, and then gently curving towards the glabella 

 at the anterior angle of the palpebral lobe, which is a 

 little forward of the middle glabellar furrow; thence 

 curving to the base of the eye, it is directed outwards. 



Fixed cheeks narrow, with a narrow posterior limb ; the 

 palpebral lobe limited by a distinct groove : frontal 

 limb much extended, and gently curving at the sides; 

 the anterior border, for about one-third or nearly one- 

 half its entire length, longitudinally flattened and as- 

 cending to the anterior margin, with a wide shallow 

 furrow between it and the posterior gently convex 

 portion of the limb. The shallow frontal furrow and 

 posterior part of the limb are sometimes visibly striated, 

 with flexuous interrupted lines which converge towards 

 the glabella ; and the bottom of the groove, in the cast, 

 is sometimes marked by a row of granules or minute 

 tubercles. 



The wide frontal limb and strong curving spine of the occipital 

 ring are characteristic features of this species. The glabella ap- 

 proaches in form that of C. iowensis ; while the frontal limb of that 



