NO. 5 UPPER CAMBRIAN TRILOBITES RESSER 83 



creases until the anterior part is nearly horizontal. In cross section 

 the glabella is moderately convex, the anterior angles not greatly 

 depressed and the anterior portion of the rim nearly flat. Surface not 

 preserved. 



Honey Creek limestone; (loc. 89V) West Timbered Hills, Arbuckle 

 Mountains, Oklahoma. 



Holotypc— U.S.N. M. No. 108810. 



BURNETIA CURTA, new species 



Plate 17, Figures 28, 29 



A cranidium has a peculiar large glabella with a nearly circular 

 front outline. Three pairs of furrows are visible. Fixigenes and eyes 

 are normal. The brim width is not much more than half the glabellar 

 length and has a narrow preglabellar area. The neck ring extends 

 into a long elevated spine that nearly equals the length of the cranid- 

 ium. Convexity is not great in cross section, but longitudinally it 

 is considerably more. 



Honey Creek limestone; (loc. 9q) Blue Creek Canyon, Wichita 

 Mountains, Oklahoma. 



Holotype.— U.S.N. M. No. 108811. 



BURNETIA CAVA, new species 



Plate 20, Figures 1-3 



A cranidium and associated libragene impression represent this 

 species. Glabella normal in size and shape although it possibly is a 

 little wider than average. Two pairs of furrows are well developed 

 and a third is faintly indicated. The neck ring may have borne a 

 spine, but if so, it was no more than a node. The brim width is 

 considerably greater than half the glabellar length. Most of it consists 

 of a concave rim with only a narrow preglabellar area demarcated by 

 a shallow furrow. Fixigenes average only a little more than a fourth 

 of the glabellar width, and the divergence of the suture anterior to the 

 eye produces large anterior angles into which the wide rim extends. 

 The sharply bowed eyes are set at a somewhat more divergent angle 

 than the dorsal furrow and are situated slightly in advance of the 

 occipital furrow, leaving a considerable posterolateral limb. The broad 

 fixigene assigned to the species has a rather large genal spine. The 

 suture evidently is intramarginal to the center, but since it is broken 

 away in front, that structure is not readily observable. 



Surface covered with evenly spaced granules except in furrows. 

 They are arranged in radiating lines on the libragene. 



