240 NEW YORK STATE MUSEUM 



Goniobasis livescens Tryon (1873. Smith. Misc. coll. no. 

 253, p. 248) 



Shell oblong and ovate ; six or seven whorls ; early volu- 

 tions slightly keeled; spire acute; sutures impressed; 

 whorls convex and crossed by plainly marked growth 

 lines; lip moderately thin, and thin callous on the colum- 

 ella. 



Fig. i62Gon- Tliis is thc most common of all the shells occurring in 



iobasis live- 

 scens these deposits along the Niagara river; it is subject to 



great variation. 



Localities. Goat island, Prospect park. Whirlpool, etc. 



Goniobasis livescens var. niagarensis (Lea) Tryon 1873 (Fig. 

 163). Melania n i a g a r e n s i s Lea (1841. Philos. soc. Phil. 

 Proc. 2:12). Goniobasis livescens var. niagarensis 

 Tryon {Smith. Misc. coll. no. 253, p. 248) 



Shell conic, obtuse, thick and smooth; spire short, whorls five or 

 six, surrounded by a sharp keel, which clearly marks the suture; 

 aperture elliptic; lip thin; columella slightly calloused. 



Prof. H. A. Pilsbry, who examined 



. -I - y ^ ^^ 



these shells, writes : " This remarkable •% t -\ {^ 



form differs from G. livescens, ,-/. {. ^^\ r -^, 



and var. niagarensis, in the per- ^S/ ^^^ %^ ' 



sistence of the peripheral keel to the ^.^^ ^^3 ^^^,^^^^,, ^vesccns var. 

 adult stage, producing a shell contour ^niagarensis 

 similar to A n c u 1 o s a c a r i n a t a; it has not hitherto been de- 

 scribed or noticed in conchological literature, and would be entitled 

 to specific rank were it not connected by intermediate forms with 

 var. niagarensis". 

 Locality. Goat island. 



Goniobasis haldemani Tryon 1865 (Fig. 164). G. 



h a 1 d e m a n i Tryon. (1865. Am. jour, conch. 1 138) 



Shell elongated, narrow and rather thin; eight or nine 

 whorls, which are flat, smooth and separated by a slightly 

 impressed suture; aperture small, subrhomboidal; lip thin. 

 Fig. 164 moderately incurved on the columellar side. 



Goniobasis -^ 



haldemani j|^-g gj-accful shcll is vcry scarce and is not represented 

 in the recent fauna. 



Locality. Goat island. 



