138 



Contributions to Palceontology. 



Facial suture vertical in its anterior line, curving at the 

 prominent palpebral lobe, and making a sharp curve 

 outwards at its lower angle. 

 Fixed cheeks narrow; palpebral lobe prominent; poste- 

 rior limb narrow triangular; frontal limb short and 

 traversed in the middle by a deep groove, from which 

 the narrow anterior margin rises abruptly : outline in 

 front a little produced in the middle. The centre of the 

 palpebral lobe is opposite the middle of the glabella. 

 In the very gibbous form of the glabella and deeply 

 marked posterior furrows, which are united across the 

 middle, and in the narrow and deeply grooved frontal 

 limb, it differs from any of the species described. 

 A pygidium associated with numerous specimens of the 

 glabella is nearly semicircular, slightly curved on the an- 

 terior margin, with a narrow prominent axis which is 

 marked by three or four annulations besides the terminal 

 one, the latter bearing two obscure nodes. The lateral 

 lobes are scarcely convex, with about three divided ribs. 



This species occurs on the Mississippi river, opposite the mouth 

 of the Chippewa, associated with Conocephalites diadematus and 

 Arionellus bipunctatus. It likewise occurs in gray ferruginous 

 sandstone at Kickapoo, associated with C. shumardi ; differing from 

 that one conspicuously in its more cylindrical glabella. 



CONOCEPHALITES SHUMARDI (n. s.). 



PLATE II, FIGS. 1 & 2 ; AND PLATE III, FIGS. 32 & 19 ? 



Glabella broad, truncate-conical, width at base greater 

 than the length, convex, gibbous in the middle, and in 

 large specimens a little flattened or depressed-convex on 

 the sides. Posterior furrows oblique, leaving a large 

 prominent posterior lobe ; middle furrow oblique and 

 deeply marked; anterior furrows shorter and less ob- 

 lique, leaving a small anterior lobe. Occipital furrow 

 somewhat strongly defined, straight in the central part, 



