8o SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. IO3 



Thus constituted, the new family is found to play a rather promi- 

 nent role in the Upper Cambrian, beginning in CrepiccpJialus time and 

 extending to about the middle of the Uppe* Cambrian. Wide variation 

 appears to exist between the ordinary swollen rim of Berkcia and the 

 enormous snout of D ok imo c c phalli s. However, since the glabella, 

 fixigenes, eyes, and furrows are much alike in these genera, the varia- 

 tions in rim shape are not to be looked u^xDn as a separating but rather 

 as a uniting feature of the family. Variability of the rim is found 

 between species of the same genus. Consequently, with such a char- 

 acteristic, wide variation must be expected in the family, and as such 

 becomes a family characteristic. 



BURNETIA Walcott, 1924 



BURNETIA INTERMEDIA, new species 



Plate 17, Figures 10, 11 



B. intermedia is one of the linguloid forms. Its glabella tapers 

 moderately to a rounded front. Two pairs of glabellar furrows are 

 clearly defined. The enlarged neck ring extends into a long, erect 

 spine. At the anterior end of the eyes the fixigenes are less than one- 

 third the glabellar width. The palpebral lobes are sharply angulated. 

 The palpebral furrow is wide and eye band heavy. The brim attains 

 a width equal to the length of the glabella exclusive of the neck ring, 

 and the preglabellar area is less than one-fifth this width. Viewed 

 from the rear the glabella is roundly convex and the fixigenes rise to 

 the eyes. Viewed from the front, however, the relative convexity of 

 the several parts is much less, though the anterior fixigenes drop 

 steeply to the depressed anterior angles. Greater convexity of the 

 cranidium is found in the longitudinal profile, attained by a rather 

 even curvature of both glabella and brim, which together form a 

 smooth sigmoid curve. Surface granulose. 



Honey Creek limestone; (loc. I2p) 4 miles southeast of Hennepin, 

 x\rbuckle Mountains, Oklahoma. 



//o/o/y/'c.— U.S.N. M. No. 108805. 



BURNETIA ALTA, new species 

 Plate 17, Figures 12-14 



The long glabella has two pairs of furrows. In dorsal view it 

 appears to be narrow and tapered more rapidly than in most species. 

 If, however, the excessive convexity in both directions is taken into 

 consideration the area of the glaljella is really large. The brim is not 

 wide, being less than half the glabellar length exclusive of the neck 



