102 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148 



Occurrence. — The holotype is from collection cnw/14, Shields 

 Ridge; the paratype from collection cnx/1, Big Creek. 



T3,^^^._Holotype : U.S.N.M. 144690. Paratype: U.S.N.M. 

 144691. 



DYTREMACEPHALUS STRICTUS Rasetti, new species 



Plate 21, figures 10-13 



Available material. — Several cranidia and one tentatively assigned 

 pygidium. 



Description. — Glabella as in D. angulatus, defined by a deeper fur- 

 row in front. Occipital ring unusually short (sag.), set off by a deep 

 occipital furrow, bearing a small node. Pits at anterior corners of 

 glabella marked in some individuals. Preglabellar field convex longi- 

 tudinally, somewhat shorter than in D. angulatus; border furrow not 

 distinctly angulate as in that species ; border somewhat less elevated. 

 Palpebral area somewhat convex, upsloping, from one-third to one- 

 half the glabellar width ; ocular ridges slightly slanted backward. Pal- 

 pebral lobe, posterior area, and facial sutures as in D. angulatus. 

 Granulation of surface rather indistinct. 



The pygidium tentatively assigned to the species is proportionately 

 shorter and wider than D. angulatus and has fewer segments both in 

 the axis and the pleural lobes. 



Discussion. — The species was compared in the description with D. 

 angulatus, from which the cranidium differs essentially in the propor- 

 tionately larger glabella. As it appears from the illustrations, consider- 

 able variation occurs among the specimens, all from one small piece 

 of rock. 



Occurrence. — Locality U.S.G.S. 2970, Vonore quadrangle, Monroe 

 County, in association with Aphelaspidella macropyge, Aphelaspis 

 palmeri, and other species. 



Ty/^^j.— Holotype : U.S.N.M. 144692. Paratypes: U.S.N.M. 

 144693. 



PTYCHOPARIIDA OF UNCERTAIN AFFINITIES 



Genus BONNETERRINA Lochman, 1936 



Type species. — Bonneterrina prima Lochman. 



BONNETERRINA APPAL ACHIA (Walcott) 



Plate 2, figures 10-18 



Lonchocephalus appalachia Walcott, part, 1916a, p. 190, pi. 35, figs. 6, 6a, 6c. 

 Lonchocephalus appalachia Walcott, Resser, 1938a, p. 86, pi. 10, fig. 30. 

 Bonneterrina appalachia (Walcott) Palmer, 1954, p. 726, pi. 80, fig. 9. 



The species is one of the most common and readily recognizable 

 fossils of the uppermost beds of the Maryville formation in the Rogers- 



