(iv) 34 PiiJ.coviolof/ia Siiiica Ser. B. 



Ceplialon tnuisvei'sely sftinieircular, moderately convex, strongly elevated near 

 the palpebral lobes, frontal margin straight. 



Glabella large, trnncato-conical in outline, moderately convex, marked by three 

 pairs of glabellar furrows; the posterior pair of furrows very broad extending obliquely 

 inward; the second pair short and slightly impressed; the anterior pair usually not shown 

 on the specimens. Occipital furrow transverse slightly arching forward near the center, 

 broad in the center and slightly impressed at both sides. Dorsal furrow clearly defined 

 extending from the frontnl rim to the postero-lateral furrows. 



Fixed cheeks nearly two-thirds the width of the glabella opposite the palpebral 

 lolie. They rise from the dorsal furrow to the palpel)ral lobes and slope with a gentle 

 curvature downward both to the frontal hmb, and some\\hat more abruptly to the pos- 

 terior margin. PalpeViral lobe strongly elevated, its length nearly equal to the frontal 

 width of the glabella; postero-lateral limbs wider than the width of the glal >ella at its 

 base ; occipital ring transverse with uniform width throughout. The frontal border turn- 

 up into a narrow elevated rim without line of demarkation from the frontal limb. 



Facial suture decends to the anterior part of the palpebral lobe directly liackward 

 but slightly inward; then, curving around the latter, passes obliquely outward, and 

 backward, cutting the border of the cephalon a little Ijack of the postero- 

 lateral angle. 



Associated free cheek about the same width of fixed eheeks opposite the palpe 

 bral lobe with a strong backward extending spine: the liody of the cheek rises with a 

 gentle covexity to the Ivase of the eve-lobe. 



The associated thoracic segment has a convex axis about the width of the flat 

 surfaces of the pleural lolte on either side, the outer half of the pleural lobe is abruptlv 

 bent downwards forming an angle of about 120 degrees with the inner portion ; surface of 

 pleurae marked by a broad and deep pleural groove which is wider on the flat part than 

 on the depressed part. 



Associated pj'-gidium semicircular in outline, with a spinose margin ; axial lobe 

 strongly convex, subconical, with a narrow and round posterior end; it is divi.led bv 

 transverse furrows into four rings and a wider terminal portion, which has a faint fifth 

 depression, indicating a fifth ring; the posterior portion of the axis slopes rather rapidly' 

 down to the margin ; dorsal furrows distinct. Pleural lol)cs very gently convex for the 

 inner half, the outer portion descending down abruptly. Surface marked by three rela- 

 tively deep and liroad furrows on either side, and one short shalbiw furrow slio-htlv 



