THE NAUTILUS. 
cc. Varix, expansion or contraction of the lip rather 
weak or inconspicuous. 
d. Keeled or angular at the basal periphery, 
rounded or flattened above the keel. 
e. Columella wide and heavy; alt. 4:6, 
diam. 44 mm. P.suscuir‘ Dkr’ Ffld. 
ee. Columella narrow; alt. 43, diam. 3°2 
mm. P. conicus Brot. 
dd. Body whorl squarish, the angles rounded ; 
columella rather wide; umbilical crescent 
defined by a carina; lip with a narrow 
varix. Alt. 5. diam. 4 mm. 
P. ORBIGNYI N. sp. 
ddd. A carina at the basal periphery, and two 
approximate keels on the back above. 
P. rricostatus Brot. 
dddd. Periphery and base well rounded; a wide 
shallow suleus or two low carinze on the 
back above. Alt. 5°5, diam. 4°8 mm. 
P. LAPIDUM SUPERSULCATUS D. VY. 
aaa. Whorls rounded, without spiral keels, angles or sulci. 
b. Globose or globose-conic ; peristome not nicked or sin- 
uous. 
c. Not banded; last whori rounded; aperture 
slightly contracted P. LapipuMm Orb. 
ce. 3-banded : lip and columella thin. 
P. PETITIANUS Orb. 
bb. Ovate, the outer or basal lip sinuous or nicked. 
ce. Outer lip expanded or flaring, its face thickened, 
with two or three nicks or sinuses. Alt. 5, diam. 
4°3 mm. P. SYKESII nD. sp. 
ce. Outer lip thin, unexpanded. 
d. Outer lip produced in a broad tongue or 
lobe, a deep rounded sinus above and 
below. Alt 5, diam. 4 mm. 
P. BISINUATUS N. sp. 
dd. Similar, but the upper sinus obsolete. 
P. BISINUATUS OBSOLETUS 0. V. 
ddd. Much more slender ; outer lip retracted at 
insertion above, sinused at base. Alt. 4°6, 
diam. 3°1 mm, P. GRACILIS 2. sp. 
