NO. 3 UPPER CAMBRIAN TRILOBITE FAUNAS — RASETTI 61 



Genus ANKOURA Resser, 1938 



Type species. — Ankoura triangularis Resser. 



ANKOURA TRIANGULARIS Resser 



Plate 3, figures 15-21 



Ankoura triangularis Resser, 1938a, p. 58, pi. 9, fig. 33. 



Available material. — Although the pygidia are quite common at the 

 type locality, the much more fragile cranidia are difficult to obtain. 

 Resser figured a fragmentary cranidium, from which the precise char- 

 acters were not clearly understood. Lochman (1940) attributed to 

 the species good limestone material from the Bonneterre dolomite; 

 however, her form belongs to a different species. Hence a brief descrip- 

 tion of the cranidium of Ankoura triangularis is in order. This descrip- 

 tion is based on exfoliated topotype material, plus specimens preserving 

 the test from another locality. 



Description. — Glabella parallel-sided, rounded in front, well defined 

 on internal impressions but barely indicated on the outer surface. 

 Occipital furrow almost obsolete on outer surface ; occipital ring very 

 short, lacking a spine. Frontal area convex and downsloping; border 

 barely represented on outer surface by a narrow striated band as in 

 many species of Kingstonia. On internal impressions there is a shallow 

 border furrow. Furrow on posterior area almost obsolete on outer 

 surface. 



Discussion. — The species differs from the material identified by 

 Lochman in two important characters: the simple occipital ring and 

 the absence of a flat border. 



Occurrence. — The type locality is U.S.N.M. 27d; red beds at the 

 base of the Nolichucky (Cedaria zone) E. of Rogersville. The speci- 

 mens figured herein are partly from the type locality, partly from a 

 limestone lens at an unspecified level near the base of the NoHchucky 

 on Comby Ridge, Howard Quarter quadrangle (author's locality cnb/ 

 10). 



Ty/^^.?.— Cotypes : U.S.N.M. 94851. Plesiotypes: U.S.N.M. 

 144608-9, 144702. 



Family MENOMONIIDAE Walcott, 1916 



Genus DRESBACHIA Walcott, 1916 



Type species. — Dresbachia amata Walcott. 



DRESBACfflA AMATA Walcott 



Plate 8, figures 1-4 



Dresbachia amata Walcott, 1916a, p. 167, pi. 26, figs. 5, 5a-c. 

 Dresbachia appalachia Resser, 1938, p. 74, pi. 10, figs. 32-34. 

 Dresbachia amata Walcott, Lochman, 1950, p. 338, pi. 48, figs. 11-14. 



