218 ^ TAL^ONTOLOGY. 



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^jp CftEPiCErHALUS 5^Lo©ANEl>LTJS) SIMULATOR n. Sp. 



Plate II, figs. 16-18. 



Head within the facial sutures quadrangular in form, exclusive of the 

 postero-lateral hmbs, slightly contracted in width in the region of the eyes. 



Glabella narrowly conical, very gradually tapering from the base ante- 

 riorly, the sides nearly straight, and rather squarely truncate in front; 

 bordered by distinct, impressed, dorsal furrows; surface evenly convex 

 throughout, and marked by three pairs of faint, moderately oblique, trans- 

 verse furrows; the two anterior pairs not extending quite one-third of the 

 width of the glabella; third or posterior pair longer, but faintly marked, 

 their inner ends strongly recurved, almost separating the posterior glabellar 

 lobes; occipital furrow distinct; ring prominent and rounded. 



Fixed cheeks of moderate width, prominent at the eye-lobes, and 

 rapidly declining in front and behind; ocular ridges faintly marked. 

 Frontal limb longer than the width of the fixed cheeks, bordered by a nar- 

 row, elevated rim, between which and the front of the glabella it is distinctly 

 convex, and the part immediately in front of the glabella more strongly 

 convex. Eye-lobes small. Posterior lateral limbs not known. Surface of 

 crust smooth. 



Specimens of movable cheeks associated with the above, and corre- 

 sponding in character, are sornewhat triangular in form; margined by a 

 slightly-flattened, elevated border of moderate width, which is continued 

 in a long, rather slender spine at the posterior angle ; inner area of the 

 cheek convex and distinctly marked with radiating striae; inner angle 

 strongly notched for the proportionally large eye-lobe. Pygidium un- 

 known. 



The species very closely resembles in form and characters the corre- 

 sponding parts of C. (X.) maculosus, but is somewhat shorter in proportion 

 to the width; the glabella is not rounded at the summit as in that species, 

 and the furrows are more distinctly marked and not so oblique, while the 

 surface does not possess the pustules characteristic of that one. 



Formation and locality/. — In limestone of the Potsdam group, at Eureka, 

 Nevada. Collected by Arnold Hague, esq. 



