24O THE CHICAGO ACADEMY OF SCIENCES. 



Dicranopeltis nasuta, n. sp., pi. xxn, figs. 5-7. 



Description. Cephalon triangular in outline, strongly con- 

 vex, extended anteriorly into an acutely pointed projection. 

 Dorsal furrows each describing a sigmoidal curve, strongly 

 defined anteriorly, nearly obsolete along the outer margin of 

 the third glabellar lobes. Glabella sub-pentagonal in outline, 

 strongly convex, not sharply defined by the dorsal furrows, 

 the general surface being continuous with that of the cheeks, 

 anterior and antero-lateral slopes protuberant. Median lobe 

 elongate, sub-pentagonal in outline, nearly twice as long as wide, 

 the anterior half sub-conical and slightly compressed laterally, 

 protuberant far beyond the anterior margin, the dorsal median 

 line straight and sloping upward from the occipital furrow to 

 the apex which is consequently elevated; in both specimens 

 examined the apex is fractured and appears to have been pro- 

 duced into a slender spine. Anterior lateral lobes large, com- 

 pound, sub-ovate in outline, completely surrounded by a deep 

 and well-defined furrow, less than half their entire surface 

 visible dorsally, their longer axes oblique to the median line 

 of the cephalon, their length about twice their width, pointed 

 at their inner extremities and rounded externally, strongly 

 convex along their median line. Third lateral lobes trapezoidal 

 in outline, nearly confluent with the median lobe within and 

 scarcely defined by the dorsal furrow externally, the surface 

 gently convex, completely visible dorsally, about one-half as 

 large as the anterior lobes. First and third lateral furrows 

 of the glabella strongly defined and confluent around the inner 

 end of the anterior lateral lobes; the second lateral furrows 

 obsolete. Occipital furrow well-defined, dividing at the pos- 

 tero-lateral angles of the median glabellar lobe, the two divisions 

 on each side passing one in front and one behind the small 

 triangular occipital lobes whose surface is slightly convex and 

 completely visible in a dorsal view; the posterior branches 

 of the occipital furrow are narrower and deeper than the median 

 portion. Occipital segment narrow. Fixed cheeks narrow 

 and linear from the lateral margins of the cephalon to the eyes, 

 back of the eyes they are triangular with a gently convex sur- 

 face which slopes laterally from the dorsal furrows with a width 

 about equaling the length of the third glabellar lobes, the an- 

 terior linear portion of the cheeks bends abruptly downward 

 in front of the eyes to the margin of the cephalon; palpebral 

 lobes very small. Free cheeks sub-quadrangular in outline, 



