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 



[Ety.: bticina, a trumpet] 



(1847. Pai- A', y- I -32) 



/^ 



Fig. 143 Pleurotomaria pervetusta 



Shells coiled, a single plane, with the 

 spire equally concave on either side and 

 all the volutions visible; outer whorl ven- 

 tricose; aU 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, pi. 4 (bis)) 



Distinguishing characters. Suborbicular form ; three- 

 Fig. i44 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 Aliller 



[Ety.: diminutive of conns, a cone] 



(182 1. 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 



