163 



ranp;emcnt, as well as in tlie number of the wliorls ; which 

 in A^ glancina is clearly six, but in A^. intricnta no more 

 than five can be ascertained. In N. glaucina the secoml anil 

 the smaller whorls are more inflated, and form a liii^her 

 spire, the decreising line ol' separation having a regular cir- 

 cular sweep ; whereas in N. intricata, beside that the whole 

 is much more depressed, the spire is not placed in the centre 

 of the whorl, but inclined to the superior side. Another 

 distingaib.hing niark is the form and situation of the umbi- 

 licus; which in N. glaucina is a simple ascending cavity, 

 intruded on by a single porcellaneous band, which proceeds 

 from the columella. In N. intricata this band is divided 

 so nearly into two, that the connection is only by a narrow 

 slip; and tbe cleft or separaiing gap, which in the smaller 

 specimen is rounded and in the larger square, exposes the 

 umbilicus above the colnmella, and therefore passes directly 

 inward, instead of obliquely upward as in N. glaucina. The 

 pillar tliiis becomes exposed uncovered by tbe band on one 

 side and the body whorl on the other, in a manner to be 

 highly characteristic of the adult shell. Tlie inferior portion 

 of the band does not stretch fully across to the wborl, 

 but is rounded off by a narrow channel, which proceeds 

 circularly to terminate within a short distance of the 

 aperture : offering, in fact, a broad and smooth porcellaneous 

 separate termination to the pillar. 



In colour N. intricata is much the most beautiful of Eng- 

 lish turbinated shells ; the two specimens difl'er much in 

 the depth, though not greatly in the distribution of their 

 tints. In the larger it is far more rich, of a fulvous brown ; 

 in the smaller lighter, and of a porcellaneous yellow. The 

 smaller whorls are in the larger somewhat livid ; yellow at 

 the separating line: in the larger, a pale yellow; and the 

 beauty of the colouring does not begin above the lower half 

 of the second whorl ; from which it descends into four regular 

 lines, at nearly uniform distances, to the margin. These 

 lines are in their ground lighter than the other portions of 

 tlie surface ; and their margins a^^e well defined ; they are 

 also portioned out and intersected, with some regularity, by 

 arrow shaped marks; of which those in the two middle are 

 the most regular. The two external lines are the widest, 

 and their arrows broader, and more separate, but that which 

 is nearest the separating line of the whorl most irregular. 

 The line nearest the umbilicus (separated from it however, 

 by a white space) is in the smallest specimen ornamented 

 with regularly formed arrows, but in the larger one side only 

 of this marking appears. The marks here denominated 

 arrows are converging lines closing to a point as they de- 



