48 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 103 



which extends to the anterior margin of the cranidium. A narrow- 

 occipital ring is indicated. 



Weeks formation; (Iocs. 3oh, i) 5 miles south of Alarjum Pass. 

 Mouse Range, Utah. 



Ilolotype. — U.S.N.M. No. 108706a; paratypes, No. 108707. 



KINGSTONIA MUCRO, new species 

 Plate 8, Figures 1-8 



This rather large species is represented hy some 20 specimens, it 

 is characterized by enormous posterolateral limbs, which give the 

 cranidium great v^idth and cause it to depart from the more nearly 

 semicircular outline of most species. The glabella is faintly indicated, 

 more particularly in the rear where shallow furrows extend forward 

 for some distance. There is a narrow rim of the usual type. The 

 eyes are of normal size and situated somewhat in front of the mid- 

 point. In cross section the head is strongly arched. The posterolateral 

 limbs continue the downward slope, with increasing curvature near 

 their distal ends. Longitudinally the cranidium is highly arched. The 

 associated pygidium, when viewed from the dorsal surface, has a 

 rounded triangular shape. In profile it is very convex. At the anterior 

 angles the sides stand vertical, but posteriorly the curvature increases 

 until at the rear of the axis the pygidium is folded under. The axis 

 is faintly outlined and in exfoliated specimens shows six rings. 

 Pleural grooves are visible. 



Sherbrooke limestone; (loc. 58f) ridge west of Mount Bosworth, 

 British Columbia. 



Holotype. — U.S.N.M. No. 108709a; paratypes, Nos. loS/oga-d. 



KINGSTONIA BOSWORTHENSIS, new species 



Plate 8, Figures 9-13 



This species has normal size and shape. The cranidium is quite 

 globular with only short posterolateral limbs, and narrow brim around 

 the front. In cross section the cranidium stands very high with its 

 greatest curvature toward the rear. Longitudinally it is curved rather 

 evenly throughout, with a slight flattening in the front fourth. The 

 associated pygidium is short and very convex. 



Sherbrooke limestone; (loc. 57p) ridge west of Mount Bosworth, 

 British Columbia. 



Holotype. — U.S.N.M. No. 108710a; paratypes, Nos. 108710b, c. 



