NO. 5 UPPER CAMBRIAN TRILOBITES RESSER 65 



ELLIPSOCEPHALOIDES CARUS, new species 

 Plate ii, Figures 7, 8 



This is a small form associated with E. argutiis. 



The subcylindrical glabella is rounded in front and has three pairs 

 of glabellar furrows. The fixigenes are convex in contrast to most 

 other species ; consequently the rather thin eye lines appear to be 

 more curved than usual. The eyes are on slightly upturned heavy 

 bands. 



Sabine formation; (loc. 12s) Ram Creek, 15 miles south of Canal 

 Flats, British Columbia. 



Holotype. — U.S.N.M. Xo. 108747a; paratype, No. 108747b. 



ELLIPSOCEPHALOIDES MONTIS, new species 

 Plate ii, Figures 9-11 



The third species from the locality is an intermediate form, ap- 

 proaching the narrow rather than the broad species. Width may be 

 an aspect as much as a reality, since the narrowness in dorsal view 

 is sometimes due to the sloping position of the anterior angles, whereas 

 other species appear wider because the anterior flanges of the same 

 size are more nearly in a horizontal position. The wide glabella of 

 E. montis is well rounded in front, and has a slight indentation at 

 the center. Glabellar furrows are reduced to faint pits. The most 

 distinctive feature is the fusing of the broad eye line with the brim, 

 which slopes back to the eyes, the latter being in a posterior position. 

 This gives the cranidium the appearance of being made up of the 

 large glabella about which is draped a wide band that slopes toward 

 the rear. Anterior fixigenes are eliminated by this juncture of the 

 eye ridge and brim. Between the eyes and glabella the fixigenes have 

 just a little more than one-third the glabellar width. In this species 

 the neck ring is rather wide. 



Sabine formation; (loc. 12s) Ram Creek. 15 miles south of Canal 

 Flats, British Columbia. 



Holotype. — U.S.N.M. No. 108748a; paratype. No. 108748b. 



ELLIPSOCEPHALOIDES BEARENSIS, new species 

 Plate ii, Figure 12 



An imperfect cranidium represents the genus in the St. Charles 

 formation of Idaho, showing that this element is also present in that 

 fauna. This species is much more like the genotype in general aspect, 

 but differs distinctly owing to the more posterior position of the eyes. 

 Glabellar furrows seem to lie lacking. The eye lines are verv mucli 



