THE NATURAL HISTORY SURVEY. 24! 



nearly vertical in position, the surface gently convex above 

 and slightly sinuous below, genal angles imperfect. Eyes small 

 elliptical in outline, the longer axes oblique, the surface convex. 

 Entire surface of the cephalon, except in the furrows and along 

 the facial suture, covered uniformly with rounded tubercles 

 of two sizes. Thorax and pygidium unknown. 



The dimensions of the best preserved specimen which has 

 been observed are: length of cephalon along median line 19 

 mm., greatest width of cephalon 24 mm., convexity 13.5 mm. 



Remarks. This species has not yet been observed in the 

 Chicago area. The types, which are the only specimens known, 

 are from Milwaukee, Wisconsin, and were collected by Mr. 

 E. E. Teller. The species is entirely different from any other 

 American form. 



Locality. Milwaukee, Wisconsin. 



Dicranopeltis teller!, n. sp., pi. xxii, figs. 8-9. 



Description. Cephalon sub-semielliptical in outline, bluntly 

 rounded in front and slightly protuberant beyond the anterior 

 margin. Dorsal furrows well defined along the outer margins 

 of the anterior lateral glabellar lobes, much less well-defined 

 adjacent to the third lateral lobes. Glabella sub-pentagonal 

 in outline, broader than long, dorsal surface gently convex in 

 front, general surface of the median and lateral lobes continuous, 

 being indented only by the narrow but sharply defined furrows 

 Median lobe broadest at the anterior margin, becoming grad- 

 ually narrower to the inner extremities of the anterior lateral 

 lobes, where it becomes abruptly wider and then continues 

 posteriorly to the occipital furrow with nearly parallel sides, 

 anterior extremity very slightly protuberant beyond the mar- 

 gin. Anterior lateral lobes compound because of the obsol- 

 escence of the second lateral furrows, sub-ovate in outline, 

 nearly twice as long as wide, nearly the whole of their surface 

 visible dorsally. Third lateral lobes quadrilateral, rhombic- 

 ovoid in outline, three-fifths as long as wide, about one-third 

 as large as the anterior lobes, the longer sides and more acute 

 extremities directed obliquely outward and forward, their 

 entire surface visible dorsally. Occipital furrow narrow and 

 deeply impressed, gently arched toward the front, dividing at 

 the postero-lateral angles of the median glabellar lobe, the 

 branches on either side passing one in front and one behind the 

 small, triangular occipital lobes which are less than one-half a's 

 large as the third lateral glabellar lobes. Occipital segment 



