THE NAUTILUS. D7 
PURPURA LAPILLUS L. 
(Extract from the report of Mrs. D. J. Wentworth. From the Transactions of the 
Isaac Lea Chapter for 1896.) 
No shell is more common on our New England shores than Pur- 
pura lapillus Linné, and yet, no shell of this region has to me, at 
least, so much of interest connected with it. 
Purpura lapillus is an humble but most worthy descendant of the 
aristocratic Muricidz, and surely the Murex is an aristocrat among 
shells, with its beautiful forms, dainty seulpturing, delicate coloring, 
and its long traditions of usefulness and importance. 
Plain in its general aspect, as it certainly is, Purpura lapillus has 
nevertheless, much in common with its more highly favored rela- 
tions. It is an old member of an ancient race, fossil remains of 
Purpura lapillus are found in the Red Crag deposits of Europe. 
This species is remarkable for its variation in solidity of shell, 
form, sculpture size, coloring and habitat. It varies in thickness 
from three-sixteenths of an inch to a shell so thin one could easily 
perforate the outer lip with a pin. In form they vary from a short 
broad shell with obtuse spire and flattened whorls to a long shell 
with acute spire and convex whorls, 
In some the coarse revolving ridges are barely discernable, while 
in others they are very prominent. The faint lines of growth which 
intersect the revolving ridges of this shell are, in some specimens, 
brought into marked prominence by rows of ruffles or scallops, and 
this seulpturing undoubtedly gave Lamarck reason for naming this 
variety Purpura wmbilicata. Many of the solid shells have rows of 
nodules or teeth within the aperture on the outer lip, 
These solid shells are usually grayish-white or white outside, with 
reddish-purple, yellow or white apertures ; but the thinner shells are 
often brown, orange or lavender, and these colors are frequently 
banded with white. I have never seen two specimens banded just 
alike. The orange and white combinations are especially pretty. 
The variety called by Lamarck P. wmbilicata, so far as I have ob- 
served, are always a greyish-white on the outside, with a reddish- 
purple aperture. This variety I have found only in a brackish 
river where they are often seen crawling about in the mud, and their 
color is so nearly the color of the mud on which they are found that 
it undoubtedly serves to protect them from the ravages of their 
enemy. Associated in this river with Purpura lapillus, and much 
resembling it in size, color and general shape, is the Urosalpinx 
cinerea. The usual habitat of the Purpura is in the nooks and 
erevices of rocks. Why do these river shells choose the mud? 
