NO. 5 UPPER CAMBRIAN TRILOBITES RESSER 33 



area and a slightly thickened rim expanding in the middle. Fixigenes 

 at their widest point are a little less than one-third the glabellar width. 

 Eyes of moderate size, rather sharply bowed. Anterior fixigenes 

 about as wide as the brim, increasing forward into the down-turned 

 anterior angles. Surface granulated. 



W^ilberns formation; (loc. 70) Baldy Mountain, 8 miles northwest 

 of Burnet, Texas; and (loc. 670) Potatotop, 7 miles northwest of 

 Burnet, Texas. 



Holutypc.—V.S.'NM. No. 108684a; paratype Nos. 108684b, c. 



DRUMASPIS WICHITAENSIS, new species 

 Plate 5, Figures 21. 22 



More than 10 cranidia of this species are in the collection. The 

 quadrate glabella is rounded by even curves at the anterior angles. 

 Glabellar furrows are developed normally except that the front pair 

 is almost obsolescent. In cross section the glabella stands completely 

 above the fixigenes, rising rather steeply at the sides and flattened on 

 top. Longitudinally the cranidium is high, with the front lobe of the 

 glabella standing vertical. Brim of moderate width, consisting of a 

 narrow preglabellar area and a slightly widened rim in horizontal 

 position. Fixigenes narrow, at their widest point being a little more 

 than one-fourth the width of the glabella. Anterior fixigenes sharply 

 down-curved, attaining a width at the anterior angles of slightly more 

 than the brim. Eyes rather small and highly bowed, with practically 

 a circular course. Posterolateral limbs curved downward into a 

 vertical position. Surface faintly marked by anastomosing lines. 



Honey Creek limestone; (loc. Qiu) i mile east of Canyon Creek, 

 15 miles northwest of Fort Sill, Wichita Mountains, Oklahoma. 



Holotypc— U.S.N M. Xo. 108680. 



DRUMASPIS CLARA, new species 



Plate 5, Figures 23-26 



Several cranidia and a libragene represent this species. 



The glabella tapers forward to a nearly circular frontal outline. 

 Glabellar furrows developed normally. In cross section this is a highly 

 convex species. The glabella, standing completely above the libra- 

 genes, rises with a rather even curvature throughout. Longitudinally 

 the cranidium also has high relief, likewise attained by a rather even 

 curvature. Brim is of normal width. The slightly thickened rim 

 widens in the middle, and occurs in a horizontal position. Fixigenes 

 slightly less than one-third the glabellar width, their anterior portion 



