TO GEOLOGY. 133 
shell thin; spire elevated and acute at apex; whorls ten, 
with an elevated band below the suture; mouth rather 
narrow, about one third the length of the shell. 
Length .5, Breadth .2, of an inch. 
Observations. A pretty little species, and may be distin- 
guished by its elevated spire, and the band which surrounds 
the whorls below the suture. 
P. Sayi.* Plate 4. Fig. 125. 
Description. Shell fusiform, turrited, longitudinally and 
thickly folded, transversely and strongly striate; substance 
of the shell rather thin; spire elevated, pointed at the apex; 
whorls eight, subcanaliculate above; mouth rather narrow, 
about one third the length of the shell. 
; Deacth Od, Breadth .2, of an inch. 
Observations. This species very closely resembles the 
last described, but may be distinguished by its more 
numerous folds and stronger striz, which are disposed to 
be larger and smaller alternately. It has a strong resem- 
blance to the species figured by Sowerby under the name 
of P. comma.t 
P. monilifera. Plate 4. Fig. 126. 
Description. Shell fusiform, turrited, transversely stri- 
ate, furnished with a larger and smaller row of tuber- 
* Named after the distinguished naturalist Thomas Say. 
| Min. Conch, plate 146, fig. 5. 
