Contributions to Paleontology. 



145 



Fixed cheeks very narrow, spreading a little in the mid- 

 dle, and separated from the elongate palpebral lobe by 

 a shallow groove : posterior limb narrow. Frontal 

 limb extended, with a shallow depression close to the 

 glabella, beyond which it is very gently convex and 

 rounded at the extremity. 



This species is peculiar, and very well marked in the 

 curving anterior margin of the frontal limb, the elongate 

 palpebral lobe, and the shallow narrow dorsal furrow, 

 which is sometimes scarcely distinct. 



Associated in the same specimens with these glabella there are 

 several movable cheeks and other parts of the body, which may be- 

 long to this species. All the cheeks have the facial suture termi- 

 nating at some. distance within the posterior angle, which is ex- 

 tended in a long curving spine. The inner angle is marked for a 

 very large eye-tubercle, corresponding to the elongate palpebral 

 lobe. 



A single pygidium in the same association has a short elevated 

 axis, with only two or three rings visible : the lateral lobes are some- 

 what flat, marked by about three ribs which terminate in a broad 

 flattened border. Some separated 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 cheek of Plate ii, figs. 45 & 46, are from this specimen. 

 The small specimen, Plate iii, f. 29, is from a different layer, at 

 Trempaleau. 



CONOCEPHALITES PATERSONI (n. s.). 

 PLATE II. FIGS. 45 & 46. 



Glabella ovate-conical, depressed-convex and slightly 

 subangular along the median line, rounded in front, 

 slightly contracted opposite the eye-lobes, a little longer 

 than its width at the base ; marked by three shallow 

 [Trans, v.] 19 



