NO. 22 CAMBRIAN TRILOBITES, 3D CONTRIBUTION RESSER 5 



Bonniella the glabella is highly arched transversely with a steep 

 anterior slope and has a tendency to expand forward. Two sets of 

 short, refiexed glabellar furrows are generally clearly defined. In the 

 three species now known the cranidium is grantilose, but such mark- 

 ings are not observable on the pygidia. 



Genotype. — Olenoides (Dorypyge) desiderata Walcott. 



Bonniella desiderata (Walcott) 



Olenoides (Dorypyge) desiderata Walcott, U. S. Geo!. Surv. loth Ann. Rep., 



p. 644, text fig. 67, 1 891. 

 Darypyge desiderata Matthew, Trans. Roj\ Soc. Canada, 2d ser., vol. 3, 

 sec. 4, p. 187, 1897. 



The glabella of this species is strongly granulose and evidently had 

 an occipital spine. The pygidium of B. desiderata has broad marginal 

 flanges which extend outward and backward at the posterior angles 

 for a considerable distance. In keeping with this development the two 

 marginal spines at the anterior angles are long and slender. 



Lower Cambrian, Winooski; (loc. 26) i^ miles southeast of High- 

 gate Springs, Vermont. 



Cotypes. — U.S.N.M. no. 18452. 



BRISCOIA Walcott, 1924 



Briscoia nevadensis, n. sp. 

 Dicellocephaliis osceola Walcott (not Hall), U. S. Geo!. Surv. Men. 8, p. 40, 

 pi. 9, fig. 25, 1884. 



This trilobite was referred to Hall's Wisconsin species of Osceolia, 

 but it clearly belongs to Briscoia. B. nevadensis is smaller than most 

 other species referred to the genus, and at the same time has a narrow 

 glabella and slender pygidial axis. 



Upper Cambrian, Hamburg; (loc. 66) north of the Dunderburg 

 mine, Eureka District, Nevada. 



Holotype. — U.S.N.M. no. 24659. 



CEDARIA Walcott, 1924 



Cedaria milleri, n. sp. 



Cedaria of. prolifica Miller, Journ. Pal., vol. 10, no. i, p. 28, pi. 8, fig. 18, 1936. 



The small Wyoming species has a less advanced direction for the 

 posterior portion of the facial suture, and a narrower preglabellar area 

 than C. prolifica. 



Upper Cambrian, Du Noir ; Warm Springs Creek, 2 miles west of 

 Du Noir, Wind River Range, Wyoming. 



Holotype. — Columbia Univ. no. 12632. 



