277 



Difitingu is h ing Characters.— Four 

 volutions, the inner ones rising mod- 

 erately above the plane of the outer 



ones; gradually and regularly expand- 

 ing whorls, with circular cross-section; 

 crowded concentric striae. 



Fig. 205. Eccyliomphalus 



Found in the Encrinal limestone, at team* (after Hail). 

 Section 5 (rare); in the Transition beds and the Upp<T Mar- 

 cellus beds, on the Lake Shore (rare). 



Genus STRAPAROLLUS. Montfort. 



[Ety. : Strabos, turned about,] 

 (1810: Conch. Syst., Vol. II., p. 174.) 



Shell discoid, depressed conical, smooth or transversely 

 striated. The whorls are rounded and closelv joined. The 

 umbilicus is very wide, exposing all the whorls. The thin, 

 complete peristome is indented by the preceding whorl. 



Straparollus rudis. Hall. 

 (Fig. 206.) (Pal. N. Y., Vol. 

 V., Pt, II., p. 58, PI. XVI.) 



Dis tingi i ish ing Ch ara c ters . — 

 About four volutions, rounded 

 above and slightly flattened 

 below ; inner volutions rising 

 above the plane of the outer 

 one; fine surface stria?, often 

 irregular and in fascicles. 



Found in the Encrinal lime- 

 stone, at Section 5 (very 

 rare). 



Fio. 206. 

 Hall;. 



Straparollus rudis (after 



Genus PLEUROTOMARIA. De France. 



[Ety. : Pleura, side; tome, cut or notch.] 



(1824: Tableau d. corps Organises Fossiles, p. 114, and Diet. Sci. Nat., T. 



XLL, p. 381.) 



Shell trochus shaped, more or less conical, with or without 

 umbilicus. Volutions angular, flattened, or rounded, their 



