56 SMITHSONIAN M ISCE[.I.ANEOfS COLLECTIONS VOL. IO3 



BYNUMIA (?) PRODUCTA, new species 

 Plate 8, Figures 35, 36 



Although this species is represented hy many specimens, only one 

 cranidium is figured. In its relatively flat anterior outline and some- 

 what upturned, thickened rim. and in the lack of divergence of the 

 anterior facial suture, this species resemhles Bloiintia. However, since 

 the fixigenes are almost triangular in shape, it is placed in Bynumia. 



Owing to the truncate anterior outline, the glabella is more quadrate 

 than usual. The very shallow dorsal furrow- converges slightly for- 

 ward and rounds off the anterior angles. A shallow occipital furrow 

 outlines a narrow ring. A deep depression crosses the preglabellar 

 area in front of the glabella, and the rim is thickened, so that it is 

 rather prominent in side view. 



Numerous pygidia are in hand, but because the specific association 

 is rather uncertain they have not been definitely assigned to the 

 species. These pygidia are characterized by the usual triangular shape, 

 axial and other features, differing from B. mollis chiefly in the abrupt 

 slopes along the outer margin, which are so steep that the edges are 

 rolled over. 



Sullivan formation; (loc. 641) Glacier Lake Canyon \"alley, 48 

 miles northwest of Lake Louise, Alberta. 



Holotype.— U.S.N. M. No. 108718. 



BYNUMIA MOLLIS, new species 

 Plate 8, Figures 37-41 



A few specimens characterized by a pronounced triangular shape 

 represent this species. The glabella is faintly outlined on the sides 

 by the dorsal furrow and in front by a change in slope. The thickened 

 rim is slightly upturned. Viewed from the rear, the glabella stands 

 above the posterolateral limbs, owing to deep notching of the posterior 

 margin at the ends of the dorsal furrow. View^ed from the front, the 

 lateral curvature is rather even, with the greatest amount along the 

 median line. Longitudinally the nearly even curvature of the glabella 

 is interrupted by the more horizontal position of the brim. The 

 pygidial axis is long, slender, and tapers gradually, reaching nearly 

 to the rear margin. A faint border is visible, and on exfoliated 

 specimens the usual segmentation is clearly defined both in the axis 

 and the pleural lobes. 



Sullivan formation ; (loc. 6411) East Lyell Glacier, 48 miles north- 

 west of Lake Louise, Alberta. 



Holotype. — U.S.N.M. No. 108719a; paratypes, Nos. 108719b, c. 



