204 RESEARCH IN CHINA. 



strong, rounded furrow that terminates in the dorsal furrow beside the glabella. 

 Cranidium with the front broadly rounded, narrow fixed cheeks, small antero-lateral 

 limbs, and narrow postero-lateral limbs, the greater part of which is taken up by the 

 strong intermarginal furrow. Glabella without traces of transverse furrows except 

 a short, slight indentation indicating a posterior pair of furrows; the glabella is 

 separated from the fixed cheeks by a very narrow, strong dorsal furrow ; the frontal 

 limb has about the same width as the frontal margin, and extends almost directly 

 downward from the dorsal furrow in front of the glabella to the sharp angle made 

 by its union with the frontal margin ; fixed cheeks about one-third the width of the 

 glabella opposite the palpebral lobes, gently convex and merging into the anterior 

 and posterior limbs; occipital ring separated from the glabella by a strong rounded 

 furrow; it is convex, broad along the center portions and narrow toward the dorsal 

 furrow. Palpebral lobe small, elevated, and about one-fourth the length of the 

 cephalon ; a low ridge extends from its anterior end forward and inward to the dorsal 

 furrow beside the glabella. Free cheeks small, gently convex, and bordered by a 

 flattened rim that is continued posteriorly into a spine ; they are separated from the 

 cranidium by the facial sutures, which cut the posterior margin a short distance 

 within the genal angles and extend with a slight sigmoid curve inward and forward 

 to the base of the palpebral lobes; curving around these they extend with a slight 

 outward curvature to the angle formed by the union of the frontal limb and margin, 

 and then curve slightly inward across the margin. 



Thorax with twelve rather narrow, nearly transverse segments; axial lobe 

 convex, with the segments slightly rounded and separated from the pleural lobes by 

 the obtuse angle formed by the union of the two lobes ; pleural lobes a little wider 

 than the axial lobe and flattened for about half their width or to the geniculation, 

 where each segment curves downward and slightly backward ; pleural furrow rel- 

 atively broad; it starts near the inner anterior edge of the pleural segment and 

 extends along the center of the segment to the geniculation, where it gradually 

 narrows to a point near the end of the flattened falcate termination of the segment. 



Pygidium small ; the subconical convex axis is marked by three shallow trans- 

 verse furrows that outline three rings and a terminal section that terminates within 

 a short distance of the posterior margin of the pygidium ; pleural lobes marked by 

 the extension of the transverse furrows on the axial lobe and the faintly indicated, 

 rather narrow border. 



Surface slightly roughened by shallow pits or a network of very minute, irreg- 

 ular ridges, the interspaces of which give a pitted appearance. 



Dimensions. There are nine entire specimens of the dorsal shield, exclusive of 

 the free cheeks. The average length is 15 mm. The different parts have the 

 following dimensions. 



Cephalon: mm. 



Length 6.5 



Width at posterior margin 9 



Length of glabella and occipital ring 5.0 



Width of glabella at base 3.5 



Thorax: 



Length 7-5 



Width at first segment 8 . o 



Width at last segment 5 



Pygidium : 



Length 2.0 



Width at anterior margin 4.5 



