NO. 3 UPPER CAMBRIAN TRILOBITE FAUNAS — RASETTI 59 



bristolensis is U.S.N.M. 36v, near Bristol, Va. Collected by the author 

 at localities cnp/17 (complete specimen), cnp/14, and cnq/14. 



Types. — Holotype of Blountia bristolensis: U.S.N.M. 94942. Holo- 

 type of Maryvillia bristolensis: U.S.N.M. 94963. Plesiotypes: 

 U.S.N.M. 144600-1. 



BLOUNTIA MIMULA Walcott 



Plate 10, figures Z-7 



Blountia mimula Walcott, 1916b, p. 399, pi. 61, figs. 4, 4a-c. 

 Blountia mimula Walcott, Resser, 1938a, p. 63, pi. 12, figs. 18, 19. 



As far as can be determined, a species of Blountia collected from the 

 lower Aphelaspis zone seems identifiable with the species. The holo- 

 type is an articulated exoskeleton of very small size and is the only 

 specimen in the hypodigm that comes from the type locality. The para- 

 types are from a different locality and appear conspecific with the 

 holotype as far as one can compare immature individuals. The cranidia 

 and pygidia illustrated herein are larger than any of the types and 

 differ only in the shallower axial furrow around the glabella, a modi- 

 fication gradually acquired during the growth of these trilobites. 



Occurrence. — The holotype is from U.S.N.M. locality 120 on Shields 

 Ridge. Under this label trilobites from both the Crepicephalus and 

 Aphelaspis zones are mixed. The paratypes are from U.S.N.M. locality 

 107c, NW, of Knoxville. The specimens illustrated herein are from 

 Oder's collection No. 2 in the Hurricane Hollow section, in association 

 with Aphelaspis walcotti, in beds higher than those holding Blountia 

 bristolensis. 



Types.— RoXoiyp^: U.S.N.M. 62781. Paratypes: U.S.N.M. 

 62782-4. Plesiotypes: U.S.N.M. 144602. 



Genus MARYVILLIA Walcott, 1916 



Type species. — Maryvillia arion Walcott. 



MARYVILLIA ARION Walcott 



Plate 9, figures 22-26 



Maryvillia arion Walcott, 1916b, p. 400, pi. 64, figs. 4-4c. 



Maryvillia arion Walcott, Rasetti, 1956, p. 1267 (includes complete synonymy) ; 

 1%1, p. 116, pi. 21, figs. 14, 15. 



Occurrence. — Type locality is U.S.N.M. 123b, J^ mile E. of Rogers- 

 ville (probably identical with author's locality cnn/2). A common 

 and diagnostic fossil of the upper part of the Crepicephalus zone. 

 Collected at localities cnk/1 (very rare), cnm/2, cnn/1, cnn/2, cnn/3, 

 cnn/4, cnn/14. 



