CONTRIBUTIONS TO PALEONTOLOGY. 159 



inner angle is marked for a very large eye-tubercle, corresponding to the 

 elongate palpebral lobe. 



A single pygidium in the same association^as a short elevated axis, with 

 only two or three rings visible : the lateral lobes are somewhat flat, marked 

 by about three ribs which terminate in a broad flattened border. Some se- 

 parated articulations of the lateral lobes of the thorax are marked by a 

 broad groove gradually narrowing to the distal extremity, which is obtuse. 



This species occurs in a ferruginous sandstone, above the lowest trilobite 

 bed on the shores of Lake Pepin. In a single specimen, of five inches square, 

 there are at least a dozen individuals. The glabella and check of Plate vii, 

 figs. 45 & 46, are from this specimen. The small specimen, Plate viii, f. 29, 

 is from a different layer, at Trempaleau. 



CONOCEPHALITES PATERSONI ( n. s.). 



PLATE VII. riGS. 45 & 46. 



Glabella ovate conical, depressed convex and slightly subangular 

 along the median line, rounded in front, slightly contracted op- 

 posite the eye-lobes, a little longer than its width at the base; 

 marked by three shallow oblique furrows which are faintly im- 

 pressed in the mould, the anterior one being near the front of 

 the glabella. Occipital furrow slightly impressed at the sides, 

 and not visible in the centre : occipital ring narrow at the 

 sides, wider and more elevated in the middle (but without ap- 

 pearance of a spine). Dorsal furrow shallow, faintly impressed 

 at the sides, and, in old specimens, not defined in front of the 

 glabella. 

 Fixed cheeks narrow^in the middle, gradually expanded towards 

 the front, and curving regularly below into the narrow posterior 

 limb : palpebral lobe not preserved in the specimens described ; 

 ocular ridges extending obliquely across the fixed cheeks ; 

 frontal limb much extended, nearly three-fourths as long as the 

 glabella, plain and gently curving downwards, a little more 

 prominent in the middle, and without transverse ridges or 

 furrows. 



Although but two individuals of this species have been obtained, the 

 characters are so peculiar as to leave no doubt as to its specific distinction. 

 The glabella is scarcely separated from the frontal limb in the larger in- 

 dividual, and the latter is very long and quite free from ridges or furrows, 

 a character not observed in any other species. A similar extent of frontal 

 limb exists in C. diadematus, G, icisconsentiis and G. hamulus ; but in these 

 it is marked by furrows or ridges, and connected with a difi"erent form of 

 glabella which is limited by a frontal furrow. 



This species is associated with ConocephalUes anatinus in a ferruginous 

 sandstone at Trempaleau, Wisconsin. 



