NO. 3 UPPER CAMBRIAN TRILOBITE FAUNAS — RASETTI 65 



NORWOODIA, species undetermined 



Plate 4, figure 24 



Cranidia of Norwoodia, too incomplete for specific identification but 

 certainly very close to the preceding species, are present in the upper- 

 most beds of the Maryville limestone in the Rogersville area. 



Occurrence. — Mar3rville limestone {Cedaria zone) ; localities cnc/2, 

 cnc/4, cnc/6. 



Disposition of material. — Figured specimen: U.S.N.M. 144611. 



Genus NORWOODELLA Resser, 1938 



Type species. — Norwoodia saffordi Walcott. 



NORWOODELLA SAFFORDI (Walcott) 



Plate 3, figures 1-6 



Norwoodia saffordi Walcott, 1916a, p. 171, pi. 27, figs. 1-lf. 



Norwoodella saffordi (Walcott) Resser, 1938a, p. 89, pi. 10, figs. 40, 41, 49, 50. 



This species is readily distinguished from all others of the genus 

 by the depth of the axial furrow and the fixed cheeks which rise above 

 the furrow itself instead of sloping down from it. Limestone specimens 

 are figured, in addition to the complete holotype exoskeleton flattened 

 in shale. The thorax of this individual seemingly has 9 segments, not 

 8 as stated by Walcott. The material from Missouri attributed to this 

 species by Lochman (1940) was incorrectly identified. 



Occurrence. — Type locality is U.S.N.M. 103, near Rogersville. The 

 species is common in the basal beds of the Nolichucky shale and inter- 

 stratified limestone lenses (Cedaria zone) . Collected at localities cnd/1, 

 cne/1, cne/2. 



Types. — Lectotype (herein designated) : U.S.N.M. 61595. Para- 

 types: U.S.N.M. 61596-600. Plesiotypes: U.S.N.M. 144612-3. 



NORWOODELLA ROTUNDICOLLIS Rasetti, new species 



Plate 4, figures 1-7 



Available material. — Numerous cranidia and a few free cheeks and 

 pygidia, preserved in limestone but mostly lacking the test. 



Description. — Glabella tapered, straight-sided, rounded in front, 

 fairly convex, rising above the cheeks, unfurrowed on outer surface. 

 Axial furrow on outer surface impressed laterally but obsolete in front ; 

 on interior impressions well defined all around. Occipital furrow im- 

 pressed throughout ; occipital ring subtriangular but rounded, lacking 

 a spine. Frontal area convex and downsloping, somewhat over one- 

 third the glabellar length, undivided by a border furrow even on inter- 

 nal impressions. Palpebral area downsloping, about 0.3 times the 

 glabellar width; ocular ridges faint. Posterior area wide (exsag.). 



