NO. 3 UPPER CAMBRIAN TRILOBITE FAUNAS — RASETTI 57 



almost obsolete posteriorly. Pleural lobes with faint border furrow 

 and wide border. Only traces of segmentation on outer surface. Sur- 

 face smooth. 



Occurrence. — Type locality is U.S.N. M. 125, 4 miles NE. of Rogers- 

 ville. Plesiotypes from the lower portion of the lower Hmestone mem- 

 ber (Crepicephalus zone) of the NoHchucky formation (loc. cnk/1, 

 cnk/3, the latter presumably identical with type locaUty). 



Types.— Uolotype: U.S.N.M. 62785. Plesiotypes: U.S.N.M. 

 144596, 144701. 



BLOUNTIALATA (Resser) 



Plate 9, figure 21 



Blountiella lata Resser, 1938a, p. 65, pi. 12, fig. Z7. 



Blountia rogersvillensis Resser, 1938a, p. 64, pi. 12, figs. 29, 30. 



The species was described under the two names on the basis of 

 cranidia preserving the test or not, respectively, as recognized by 

 Lochman and Duncan (1944). This trilobite was found as a rare 

 member of the faunule of the upper portion of the lower hmestone 

 member of the Nolichucky. The previous descriptions and the illus- 

 trations supply the available information about the species. 



Occurrence. — The type locality for Blountiella lata is U.S.N.M. 125 

 and that for Blountia rogersvillensis is U.S.N.M. 121a, both 4 miles 

 NE. of Rogersville. The author collected the species from the upper- 

 most beds of the lower limestone member of the Nolichucky (Crepi- 

 cephalus zone) at locality cnn/3. 



Types. — Holotype: U.S.N.M. 94961. Holotype of Blountia rogers- 

 villensis: U.S.N.M. 94959. Plesiotype : U.S.N.M. 144597. 



BLOUNTIA MONTANENSIS Duncan 



Plate 9, figures 13-20 



Blountia montanensis Duncan, in Lochman and Duncan, 1944, p. 53, pi. 8, figs. 

 29-34. 



This species, described from Montana, is common in the Crepi- 

 cephalus zone in Tennessee. There is some variation in the length of 

 the preglabellar field, elevation of the anterior border and depth of the 

 axial furrow on the cranidium, but since all intermediate forms occur 

 in the same beds, these features should be interpreted as intraspecific 

 variability. 



Occurrence. — Localities cnk/1, cnm/2, cnn/1, cnn/3. The species 

 is more common in the lower portion of the lower limestone member 

 of the Nolichucky {Crepicephalus zone) but ranges throughout this 

 limestone. 



Ty/j^j.— Plesiotypes: U.S.N.M. 144598-9. 



