24O NEW YORK STATE MUSEUM 



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



253.. P- 2 48) 



a 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. 16a Gon- This is the 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 niagarensis Lea (1841. PJiilos. 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 



these shells, writes: "This remarkable \ . i 



form differs from G. livescens, 4 ■•,■■;;, ( mm ?3QS 

 and var. niagarensis, in the per- 'v^j/ ' *> \&-- 



sistence of the peripheral keel to the F . g _ lg3 Goniobasis livesecns m) , 

 adult stage, producing a shell contour nla £ areiisis 

 similar to Anculosa carinata; 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. 



G-oniobasis haldemani Tryon 1865 (Fig. 164). G. 



haldemani 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 J 



haldemani j^ s graceful shell is very scarce and is not represented 

 in the recent fauna. 



Locality. Goat island. 



