82 SMITHSOXIAN M ISCEF.I.ANF.OrS COLLF.CTIONS VOL. IO3 



fact, taken as a whole, the cranidium gives the impression of circu- 

 larity. At the same time B. exilis is a convex form, the glaljella 

 standing high above the fixigenes and tVie brim continuing the down- 

 ward slope of the anterior portion of the glaljella. Eyes, fixigenes, 

 glabellar furrows, and eye bands are similar to corresponding parts in 

 species of average structure for Buructia. The brim width is about 

 three-fourths the glabellar length and has only a narrow preglabellar 

 area. Viewed from the front, the brim has an even curvature between 

 the depressed anterior angles. In cross light several shallow secondary 

 furrows parallel to the front margin are visible, but they may repre- 

 sent doublure impressions. Surface of elevated portions granulated. 



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

 Mountains, Oklahoma. 



Holotype.—V.S.'nM. No. 108808a ; paratypes, Nos. 108808b, c. 



BURNETIA ECTYPA, new species 

 Plate 17, Figures 30, 31 



Only a small fragment in addition to the beautiful holotype cranid- 

 ium has been found. The glabella, well rounded in front, has the 

 rear pair of glabellar furrows of normal development and very shallow 

 identations indicating the second pair. No nuchal spine and practically 

 no preglabellar area remain. The brim is about two-thirds the length 

 of the glabella including the neck ring. Longitudinally the glabella is 

 rather highly and evenly convex. The concave brim is set at such an 

 angle that it makes the cranidium as a whole high. In cross section 

 the glabella rises steeply above the dorsal furrow to a somewhat 

 angulated median portion. The rim is evenly convex between the 

 moderately depressed anterior angles. 



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

 Mountains, Oklahoma. 



Holotype.— \5.Sy.^M. No. 108809. 



BURNETIA LINGULA, new species 

 Plate 17, Figures 32, 33 



A single cranidium of another linguloid form, much like B. extcnsa, 

 has greater convexity and a brim of the same width as the glabellar 

 length. A narrow preglabellar area remains. Viewed from the side 

 the glabella is gently convex at the rear, increasing its rate of curva- 

 ture until the anterior third is turned sharply downward. The pro- 

 clivity of the glabella is continued by the brim at a decreasing rate 

 for nearly half its width, beyond which point the rate of slope de- 



