INSTITUTE OF SCIENCE, PHILADELPHIA. 109 



the costse obsolete, resolved into a number (about eight) of shoulder- 

 nodes, which break the circumferential outline into a polygon ; aperture 

 greatly exceeding the spire in length ; columellar folds three, transverse, 

 situated immediately below the body of the shell ; revolving lines of sur- 

 face feebly defined, almost obsolete on the body-whorls, except on the 

 siphonal tract, where they are well-marked, and of equal significance. 



Length (of fragment, lacking probably two-thirds of an inch below, 

 and a third of an inch above), 1.8 inch ; width, .8 inch. 



Vasum subcapitellum, nov. sp. Fig. 44. 



Shell elevated, pagoda^form ; whorls of the spire about seven in 

 number, coronated and strongly costated, the concentric lines (two or 

 three) below the shoulder prominent, those on the rugose shoulder less 

 distinct ; the coronary spines prominent, sharp, and directed outwardly ; 

 body-\vhorl with a single row of sharp basal spines, about six in number, 

 below which are two not very prominent lines, and above, some seven 

 sharply-defined concentric ridges, separated by interstitial finer lines ; 

 shoulder of whorls elevated ; outer lip strongly lined internally ; inner 

 lip well expanded, but leaving a broadly-open umbilicus ; columellar 

 plaits three, transverse, the upper the largest ; surface of shell covered 

 with rugose lines of growth. 



Length, 1.4 inch; width, .7 inch. 



This shell very closely resembles the recent Vasum capitellum, espe- 

 cially the young of that form, and might at first sight be readily 

 mistaken for that species. It differs in its less foliaceous aspect, smaller 

 size, the elevation of the shoulder (nearly flat in V. capitclliuii), and in 

 the presence of only a single row of basal spines (instead of two). I 

 believe there can be no doubt as to its being the ancestor of the living 

 form. 



Voluta musicina, nov. sp. Fig. 45. 



Shell cylindriform ; spire elevated, of about seven volutions ; whorls 

 convex, strongly costated, impressed below the suture, so as to divide 

 the costae into a double series ; costas very prominent, obtuse, about ten 

 on the body-whorl, crossed at right angles by rather distantly-placed, 

 elevated revolving lines ; outer lip with a reflected border ; inner lip 

 distinct in its lower half, plicated over its entire extent, the plicae increas- 

 ing in size from above downward, nearly transverse in direction ; aperture 

 considerably over half the length of shell, narrow. 



Length, nearly two inches ; greatest width, at about the middle of 

 the shell, slightly exceeding one inch. 



The shell bears a very general resemblance to the recent Valuta 

 vii/sica, of which it may be considered an immediate ancestor, differing 

 from that form principally in its narrower outline, the depressed shoulder 



