NIAGARA FALLS AND VICINITY 213 



Pleurotomaria pervetusta (Conrad) (Fig. 143) (1852. Pal. 

 N. Y. 2:12, pi. 4 (bis)) 



Distinguishing characters. Small size; depressed conic spire, the 

 volutions strongly embracing; whorls 

 about four, gradually enlarging; large um- 

 bilicus extending to the apex. 



Found in the upper Medina sandstones 

 of the Niagara sections. Also at Lockport 

 (Hall). 



Genus bucania Hall /Vfl ? J ^\ 



[Ety. : buciua, a trumpet] I ^""^ ' ^ 



(1847. Pal. N. Y. 1 -.32) \Zs y , J i 



V .■■. 



Shells coiled, a single plane, with the .. 5 .?. .. 



spire equally concave on either side and 



n .■• , '. . .. , , , Fig. 143 Pleurotomaria pervetusta 



all the volutions visible; outer whorl ven- 



tricose; all whorls embracing to some extent, having an inner con- 

 cavity: aperture rounded, oval, somewhat compressed on the inner 

 side from contact with preceding whorl. 



Bucania trilobata (Conrad) (Fig. 144) (Hall. 1852. 

 > Pal. N. Y. 2:13, pl- 4 (bis)) 



Distinguishing characters. Suborbicular form; three- 

 Fig. 144 Bucania lobed volutions, all of which are visible ; last whorl 



trilobata 



greatly expanded; aperture wider than long. 

 Found at Medina and Lockport and fragments in the upper 

 Medina of Niagara indicate its presence there. 



Class CONULARIDA 



Paleozoic mollusks of doubtful systematic position; resembling 

 some modern Pteropoda, but only distantly and ancestrally related 

 to them. Shells conic or tubular, elongate, septate and variously 

 ornamented. 



Genus conularia Miller 



[Ety.: diminutive of conus, a cone] 



• (1821. Sowerby. Mineral conchology, 3:107) 



Shell elongated, pyramidal, with the transverse section varying 

 from quadrangular to octagonal; angles indented by longitudinal 

 grooves. The surface is variously ornamented by transverse or 



