36 AMERICAN MARINE CONCHOLOGY. 
It is a very pretty shell; a single specimen was found in a fish 
off Charleston bar; fourteen fathoms. It resembles N. incrassata 
of England, and we have seen it in collections labelled ‘* N. am- 
bigua, Mor., West Indies.’ 
This species I have not been able to identify. It has never 
been figured, and, as only a single specimen was obtained, it may 
be considered a doubtful species. 
Genus PURPURA, Bruguiere. 
Encyc. Method., i. 15, 241. 1789. 
Shell oblong-oval, last whorl large; spire short ; aperture ovate, 
large, with an oblique channel or groove at the forepart; colu- 
mella flattened; outer lip simple. 
There are about one hundred and fifty species; inhabiting the 
‘seas of temperate and warm climates. 
1. P. napriuus, Linneus. Figs. 56, 57. 
(Buccinum:) Syst. Nat., edit. xii. 1202. 
Shell ovate, thick and solid ; spire short and very acute, suture 
impressed ; whorls five, with deep revolving furrows and inter- 
vening ribs, and transverse raised scale-like wrinkles. Aperture 
ovate; lip arched and subacute, with obscure revolving ridges 
within the margin. Pillar lip produced, concave externally at the 
base; canal short. Operculum horny, oval. Color from white, 
through various shades of yellow, to dark red, sometimes with a 
white band. 
Length 31, diam. 17 mill. 
Inhabits rocky shores. It is a very variable species in coloration 
and form, and is equally common on both sides of the Atlantic. 
Entire Coast, Greenland to Florida. (Europe.) 
2. P. FLrormpana, Conrad. Fig. 58. 
Journ. Philad. Acad. Nat. Sci., vii. t. 20 f. 21. 1837. 
Shell oblong-ovate, conspicuously attenuated at both ends, spire 
sharp; whorls depressed and finely noduled around the upper part, 
transversely very closely ridged and grooved throughout, interior 
of the aperture deeply grooved. Bluish-gray, indistinctly and 
irregularly encircled with narrow yellow zones, and rather indis- 
tinctly painted with blackish longitudinal waves, columella and 
interior of the aperture orange-yellow, frequently banded within. 
North Carolina to Florida. 
