D is t in i;- u is li in ^i>- Clin ni ctcrs.— Four 

 volutions, the inner ones rising- niod- 

 erateh' above the pLane of the outer 

 ones; gradually and regularly expand- 

 ing whorls, with circular cross-section ; 

 crowded concentric stria\ 



Found in the Encrinal limestone, at 

 Section 5 (i-are ); in tlie Transition beds and the U])per Mar- 

 cellus beds, on the Lake Shore ( rare ). 



Fig. ~05 Eccijliomphalus 

 laxuK Cafter Hall). 



Genus STRAPAROLLUS. Montfokt. 



[Ety. : St mhos, turned about.] 

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



Shell discoid, depressed conical, smooth or transversely 

 striated. The whorls are rounded and closely joined. The 

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

 complete peristome is indented by the pi-ecediag whorl, 



Stkaparollus rudis. Hall. 

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

 v., Pt. II., p. 58, PL XVI.) 



I)istin<j;uishing Clia rn cters. — 

 About four volutions, rounded 

 above and slightly flattened 

 below ; inner volutions rising- 

 above the plane of the outer 

 one; fine surface strijp, often 

 irregular and in fascicles. 



Fouud in the Encrinal lime- 

 stone, at Section 5 (very 

 rare). 





StvaparoUns riidis (after 



Genus PLEUROTOMARIA. De France. 



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



(1834: 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 



