48 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148 



Occurrence. — Uppermost beds of the lower limestone member of 

 the Nolichucky (Crepicephalus zone) ; locality cnn/3. 



Disposition of material. — Figured specimens : U.S.N.M. 144571. 



Genus COOSELLA Lochman, 1936 



Type species. — Coosella prolifica Lochman. 



COOSELLA ANDREAS (Walcott) 



Plate 1, figures 1^ 



Blountia andreas Walcott, 1916b, p. 398, pi. 64, fig. 2. 

 Coosella andreas (Walcott) Resser, 1938a, p. 70, pi. 13, fig. 11. 



Available material. — The holotype is a cranidium. Two cranidia and 

 two associated pygidia collected by the author allow a more complete 

 description. The cranidia differ from the holotype in the slightly less 

 downsloping attitude of the anterior border, but such differences are 

 common in obviously conspecific populations. 



Description. — The pygidium has a very prominent, tapered, rounded 

 axis reaching more than two-thirds of the pygidial midlength ; it shows 

 3 rings and a terminal section extended into a low, broad postaxial 

 ridge. Pleural lobes with unusually strong convexity, sloping down 

 steeply to a narrow, poorly defined, concave border. Pleural platforms 

 furrowed for a short distance, with 2 pairs of furrows and 1 pair of 

 interpleural grooves indicated, all ending on the line that marks the 

 inner edge of the doublure. Posterior margin in dorsal view showing a 

 narrow notch between rounded lobes, in posterior view strongly raised 

 medially. Surface of test smooth. The strong convexity of the pygidium 

 distinguishes the species from all others attributed to the genus. 



Occurrence. — Uppermost beds of Maryville limestone {Cedaria 

 zone). Type locality is U.S.N.M. 102a, east of Roger sville. Collected 

 by the author at locality cnc/2. 



Types.— Rolotype: U.S.N.M. 62823. Plesiotypes: U.S.N.M. 

 144572. 



COOSELLA RESSERI Rasetti, new name 



Plate 1, figures 5-7 



Uncaspis tennesseensis Resser (part), 1938a, p. 105, pi. 9, fig. 20 (only). 



Available material. — The pygidium, holotype of Uncaspis tennes- 

 seensis, and 2 additional pygidia, all preserved in limestone but ex- 

 foliated. 



Description. — Pygidial axis slightly tapered, very prominent, show- 

 ing 3 rings plus a terminal section, extended into a low postaxial ridge. 

 Pleural platforms convex and strongly downsloping, showing several 

 pairs of shallow furrows and interpleural grooves, all curving back- 

 ward. Pleural region extended into a pair of slightly concave, horizon- 



