ei ALBATROSS EXPLORATIONS. A8l 
whorl, smooth, with the exception of a distinct median keel on the two 
lower whorls. Sculpture consists of about seventeen very thin, slightly 
raised, strongly recurved riblets extending from suture to suture, ren- 
dered nodulous by the intersection of a rather broad, smooth, rounded 
median carina. The greatest curvature of the transverse riblets is 
above the carina on the wide, slightly concave subsutural band, which 
is crossed also by the lines of growth, and in some specimers by nu- 
merous microscopic revolving strie. On the body-whorl, from the pos- 
terior end of the aperture to the end of the canal, there are about twelve 
rather fine, smooth, rounded cinguli; the first, situated just above the 
suture and a little wider and more prominent than the others, is ren- 
dered nodulous by the crossing of the transverse riblets, at which they 
abruptly end, and is separated from the second by a rather wide, smooth: 
space, crossed only by the microscopic lines of growth; the space be- 
tween the others decreases so that, on the canal, they are rather close 
together. On some of the specimens, there is an additional cingulus 
midway between the carina and the first cingulus; and three or four 
of the transverse riblets, and sometimes all of them, on the dorsal sur- 
face, extend as nearly straight lines to the base of the canal. The ap- 
erture, in immature specimens, is rather broad-ovate, with a thin, 
slightly curved outer lip, having a very shallow, wide posterior sinus, 
and the columella has a slight sigmoid curvature, most decided at its 
posterior third, while in more mature specimens the aperture is very 
narrow-oblong, with a very much thickened outer lip, forming a con- 
spicuous white varix with a thin brown edge bending in and partly 
closing the aperture, and with a deep, narrow, oblique sinus considera- 
bly below the suture. Somespecimens have about four smooth, raised, 
rounded, revolving threads on the interior of the aperture, which form, 
by their abrupt terminations, conspicuous nodules within the margin of 
the outer lip. The outer lip also increases posteriorly and joins the 
inner lip alittle below the suture, thus considerably shortening the 
aperture. Columella nearly straight, with a row of from four to six 
very minute white crenulations just within the thin free edge of the in- 
ner lip; canal very short, narrow at its base, but suddenly widened by 
the abrupt outward turning of the lip. 
Color of fresh specimens, when dry, amber, with lighter tinted carina, 
and red-brown edged aperture; some specimens are also irregularly 
spotted with red-brown. 
Length of a medium-sized mature specimen, 5™"; its breadth, 2™™;. 
length of aperture, 1.75"; its breadth, .5™™. A specimen without the 
thickened lip has an aperture 2™™ long and nearly 1™™ broad. 
Found in large numbers, both living and dead. 
Mr. W. H. Dall considers this shell identical with a species from 
Florida to which he has given the name, melanitica (MSS.), but admits 
a varietal difference. 
