GASTEROPODS 381 
to Italy, where they are used in cameo-cutting. It is owing to the fact 
that the substance of these shells is deposited in layers of different colors 
that they are available for this purpose. There are about fifty species 
of helmet-shells, the one most valued for cameo-cutting bemg known 
as the black helmet, C. Madagascarensis. 
C. testiculus. A species found outside of the West Indies only at 
Key West and at Hatteras, where the Gulf Stream has brought so many 
West Indian forms, and left them at the point where it takes its oblique 
course away from the shore. This pretty species is smaller than the 
others just: described. It has a low, depressed spire; longitudinal ribs 
crossing wide, flat revolving ribs; a long, narrow aperture; and a 
reflexed and thickened outer lip, also toothed. The columella is thick- 
ened and ribbed. The anterior canal is recurved over the back of the 
shell, as is usual in the genus. The color is bluish, with dark spots. 
There are square black spots on the reflexed lip; the aperture is pink, 
and the teeth and columellar ribs white. This species is exceedingly 
common at Nassau, and plays havoe with the more slowly moving 
bivalves, which it devours. (Plate LXXI.) 
C. injlata. Perhaps the commonest species of Cassis on our coast. 
It is reported to be common at Beaufort, South Carolina, yet it is not so 
frequently met with out of the West Indies as some earlier collectors 
would have us believe. Beach-worn specimens, however, are not 
unusual all along the Florida coast. It attains a size of from three to 
four inches, and is a rounded, globose, ventricose shell, with a higher spire 
than is usual in this genus. The surface is almost smooth, the series of 
revolving ribs being scarcely raised on the body-whorl. The lip is 
thickened and reflexed, with prominent lamelliform teeth which continue 
as internal ribs. The lower portion of the columella is calloused and 
roughly granulated. The color is bluish-white, glazed, with large square 
brown spots. The region of the aperture is pure white. The collector 
should not remain content with a specimen or two of the poor beach-worn 
shells of this species. In general, this advice applies to the collection of 
all specimens. One can get no idea of the sculpturing and painting of 
shells from dead and worn specimens. Itis quality rather than quantity 
that makes an interesting cabinet. (Plate LXXI.) 
FAMILY MURICIDE 
SUBFAMILY MURICINE 
It seems like making a long leap to pass suddenly from the 
Cassidide to the Muricide. In the natural biological order, as it 
appears in our present state of knowledge, a host of families and 
genera intervene between these two. But they are omitted here, 
either because they do not conspicuously occur upon our own 
shores, or because they are free-swimming pelagic mollusks, 
which live only far out at sea and rarely are found on the beaches. 
The family Muricide is an exceedingly large one, including a be- 
