THE NATURAL HISTORY SURVEY. 249 



entire width of the glabella, becoming regularly narrower back- 

 ward to about the position of the line joining the eyes, where 

 its width is less than half that at its anterior margin, and then 

 slightly expanding again to the occipital furrow; first lateral 

 furrows strongly defined and continuing backward on either 

 side of the median lobe to the occipital furrow; lateral lobes 

 not divided but consisting of a single pair which are compound, 

 being formed by the coalescence of the first and second lateral 

 lobes, they are large, each one being about two-thirds the size 

 of the median lobe, convex, sub-elliptical in outline, their 

 anterior extremities not as far forward as the median lobe, 

 extending backward to the occipital furrow; second and third 

 lateral furrows and the third lateral lobes obsolete. Occipital 

 furrow broad, shallow and ill-defined back of the median glab- 

 ellar lobe, becoming narrower and more sharply impressed 

 laterally, not enclosing a pair of occipital lobes, apparently 

 contiguous laterally with the posterior cheek furrows. Occi- 

 pital segment rather broad with parallel margins. The cheeks 

 imperfectly preserved. 



Pygidium sub-pentagonal in outline. The axis strongly 

 convex from the anterior margin to near the middle where it is 

 rather abruptly depressed and continues to the posterior mar- 

 gin as a depressed post-axial region in the same general plane 

 with the pleural lobes, it is well defined by the dorsal furrows, 

 and at its anterior extremity occupies about one-third the 

 entire width of the pygidium; the dorsal furrows converge 

 posteriorly to a little back of the elevated portion of the axis, 

 the axial region at this point being less than one-half its width 

 anteriorly, from here the dorsal furrows continue posteriorly 

 sub-parallel with each other becoming slightly divergent again 

 toward their posterior extremities; anteriorly the axis has two 

 distinct annulations with a third less distinct one, the third 

 transverse furrow not being continuous across the median por- 

 tion; the posterior margin of the axial region is broadly sinuate. 

 The pleura nearly flat, divided into three pairs of broad, deeply 

 grooved segments, the lateral extremities of the two anterior 

 segments on each side are produced into bluntly rounded, 

 backwardly directed free points, and between the angular 

 extremities of the third pair of segments lies the sinuous pos- 

 terior margin of the axial region. The entire surface of the 

 head and pygidium are covered with depressed, rounded and 

 crowded papillse of rather large size. Thorax unknown. 



