NO. 22 CAMBRIAN TRILOBITES, 3D CONTRIBUTION — RESSER 9 



Inasmuch as Goniodiscus proposed by Raymond in 191 3 was pre- 

 viously used in 1842, Howell substituted Calodiscus. 



Therefore, when the history of these generic names is reviewed 

 Dawsonia appears to have been clearly established and subsequent 

 changes were unnecessary. 



Besides the genotype the following species seem to belong to 

 Dawsonia: 



Goniodiscus lobata (Hall) 

 Calodiscus oclandicus Westergaard 

 Goniodiscus parkeri (Walcott) 

 Miscrodiscus sctdptus Hicks 

 Calodiscus foveolatus Howell 



The family name would, according to the rules, become Dawsonidae, 

 which would contain the genera Dawsonia Hartt, Eodiscus IMatthew 

 and Weymoiithia Raymond. 



Genotype. — Daiwonia da^vsoiii Hartt — Alicrodiscus dawsoni Bil- 

 lings. 



DUNDERBERGIA Walcott, 1924 



Dunderbergia anyta (Hall and Whitfield) 



Crcpiccphalus (Loganelhis) aiiytiis Hall and Whitfield, U. S. Geol. Expl. 



40th Par., vol. 4, p. 219, pi. 2, figs. 19-21, 1877. 

 Liostracns anytiis Brogger, Geol. Foren. Stockholm Forhandl., vol. 8, p. 212, 



1886. 



This form is not quite typical of the genus because it is narrow. 

 Also, the surface is more heavily lined than usual. 



Upper Cambrian, Secret Canyon ; Schellbourne, Schellbourne 

 Range, Nevada. 



Lectotype and paratype. — U.S.N.M. no. 24576. 



EHMANIA Resser, 1935 



Ehmania tetonensis (Miller) 

 Marjiimia ? tctoneiusis Miller (part), Jourii. Pal., vol. 10, no. i, p. 33, pi. 8, 

 figs. 19, 20, 1936 (not fig. 21^: Kootcnia tetonensis). 



Middle Cambrian, Wolsey ; South Fork, Teton Creek Canyon, 

 Teton Range, Wyoming. 



Cotypes. — Columbia Univ. no. 1260"/. 



Ehmania adina (Walcott) 

 Ptychoparia adina Walcott, Smithsonian Alisc. Coll., vol. 67, no. 3, p. 78, 

 pi. 12, figs. 3-3b, 1917. 



Middle Cambrian, Stephen?; (loc. 57q) Mount Bosvvortb, British 

 Columbia. 



Cotypes.— {J.S.^M. nos. 64383-5. 



