K. J. Hush — Mollasca of (J(vpe Sattcras. 459 



brown just below the suture, and a similar one on the middle of the 

 body-Avborl. 



Length, o-5'"'"; breadth, 3"""; length of aperture, 3"'"' ; its breadth, 



1 mm 



A few dead specimens, in 10 to 17 fathoms. 

 Mangilia melanitica Ball, variety oxia Bush. 



Report U. S. Com. Fish and Fisheries, p. 78, 1883, for 1885. 



Plate XLV, figures 3, 3a. 



Shell small, slender, fusiform, lustrous, transparent, glassy, with a 

 tall, regularly tapered, acute spire. Whorls eight slightly convex, 

 angulated and cariuated. Suture defined by a distinct, smooth, 

 rounded thread. Nucleus large, acute, nearly smooth, of three and a 

 half rapidly tapering coils, witli a small, very prominent, decidedly 

 upturned apical whorl ; the two lower whorls have a distinct median 

 keel. The sculpture consists of about seventeen very thin, sligthly 

 raised, strongly recurved riblets extending from suture to suture, 

 rendei'ed 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 

 bantl, which is crossed also by the lines of growth, and in some speci- 

 mens, by numerous, microscopic, revolving striie. On the body- 

 whorl, from the posterior end of the aperture to the end of the canal, 

 there are about twelve rather fine, smooth, rounded cinguli. The 

 first, a little wider and more prominent than the others, situated just 

 above the suture, is rendered nodulous by the crossing of the riblets 

 at which they abruptly end, and is separated from the second by a 

 quite wide, smooth space ; the distance between the others decreases 

 so that, on the canal, they are quite close together. On some of the 

 specimens there is an additional line midway between the carina and 

 the first cingulus ; and three or four of the riblets, and rarely all of 

 them, on the dorsal surface extend, as nearly straight lines, to the 

 base of the canal. The aperture, in immature specimens, is rather 

 broad-ovate, with a thin, slightly curved outer lip with a very shal- 

 low, wide posterior sinus and the columella has a slight, sigmoid cur- 

 vature, while in more mature specimens the aperture is very narrow, 

 oblong, with a very much thickened outer lip, forming a conspicuous 

 varix with a thin, brown edge bending in, partly closing the aper- 

 ture, and with a deep, narrow, oblique sinus considerably below the 

 suture. The outer lip also increases posteriorly and joins the inner 



