344 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53 



spine as a nearly flat border that in a small cephalon, 3.5 mm. in 

 length, has a short, blunt intergenal spine close to the genal spine, 

 very much as in CaUavia broggcri [pi. 27, fig. 1]. Glabella nar- 

 row, convex and contracting- slightly at the sides from the occipital 

 ring to the anterior lobe which widens and curves abruptly down- 

 ward nearly to the front marginal rim of the cephalon ; it is divided 

 by four nearly transverse furrows into three narrow transverse 

 lobes and a large anterior lobe ; the anterior lobe expands in front 

 of the eyes and curves over and down to just within the front mar- 

 ginal border which is broadly and slightly arched upward at its 

 lower margin in front of the glabella : the two posterior transverse 

 lobes of the glabella are longitudinally subequal in width and wider 

 than the second lobe ; occipital ring widening from the sides toward 

 the posterior center where a small node occurs. Eyes small, about 

 one-third the length of the cephalon: they rise abruptly from the 

 cheeks and are very prominent when viewed from the side, although 

 not raised above the level of the glabella ; palpebral lobe defined 

 from the anterior lobe of the glabella by a shallow furrow ; it arches 

 backward close to the glabella to a point opposite the center of the 

 posterior transverse glabellar lobe; the cheeks slope rather abruptly 

 up from the marginal border to the base of the eye ; the interior of 

 each cheek is marked by a narrow depressed line or furrow that 

 extends with a gentle sigmoid curvature backward and outward to 

 where it crosses the marginal border a short distance from the genal 

 spine ; in one specimen it crosses the border obliquely and disappears 

 at the intergenal spine ; this furrow appears to indicate the course 

 of a facial suture back of the eye that is in a state of symphysis. In 

 my original description [Walcott, 1884, p. 28] I called this line the 

 facial suture. No trace of anything indicating a facial suture has 

 been seen in front of the eye. 



Surface minutely punctate with faint, irregular, very slightly 

 elevated, narrow ridges that form an irregular network of elongated 

 meshes. The outer surface usually adheres to the matrix to such 

 an extent that only a few fragments show it at all. 



Dimensions. — The largest cephalon in the collection has a length 

 of 13 mm., width 26 mm. ; convexity at anterior lobe of glabella 

 4 mm. Width of glabella at occipital ring 5 mm., at widest part of 

 anterior lobe 5.5 mm. ; length of eye 3.5 mm. 



Thorax and pygidium unknown. 



Observations. — This very unusual form is abundantly represented 

 in the Nevada and Utah area of the Cordilleran Cambrian bv manv 



