342 MOLLUSCA. 
resembles an elevated cone. This form appears to be what has been 
named P. Magellanica, by Gmelin (Woop; Index, f. 69, fusca, CHEMN.; 
Conch., tab. 5, f. 10). The more depressed ones, with an anterior 
apex, may be such as are named P. ferruginea (Woop, f. 32). The 
external colour varies from a very dark slate, through brown to ferru- 
ginous, or dusky horn-colour. It is uniform in the majority of 
instances, but with the ribs darker than the interstices in some cases ; 
the ribs are pretty uniformly thirty in number, usually irregularly al- 
ternating larger and smaller. 
The interior is more commonly plumbaginous having the margin and 
central spatula very dusky brown, with golden reflections, and with more 
or less white callus at the inner margin of the muscular impression. 
Sometimes the whole interior is of this dark gilded brown; but it is 
rare that even then there is not some minute white spot near the 
muscular impression. 
Animau. “In all varieties, however, the animal is found precisely 
the same, except some little differences in the colour of the foot, as to 
depth of shade. The head, which is small for so large a Patella, is of 
a delicate rosy-white on the upper part, passing into colourless toward 
the neck and mouth. In front it is prolonged into a short proboscis, 
opening transversely in form of an ellipse, and forming a sort of 
margin above and around the mouth. Tentacles, long and taper, arise 
from about the middle of the head, and instead of being carried in a 
right line, they curve so as to resemble a pair of cow’s horns in minia- 
ture. Colour yellowish-white, except a stripe of dark purple on their 
back, reaching from just above their base to tip. ‘The eyes are very 
indistinet, on the back and near the origin of the tentacles. Foot nearly 
circular, very muscular, in general of a dark bluish slate-colour; mantle 
and branchie pale yellow. The latter surround the whole body like 
a delicate, fibrous fringe. The cirrhi with which the mantle is fringed 
are short, but conspicuous, purple at base, and yellowish at tip, and 
when contracted, resembling small, black points near the edge of the 
mantle. ‘These cirrhi correspond to the sinuosities in the margin of 
the shell. The surface of the foot, above the muscular portion, is coated 
with a soft, springy integument, of perhaps one-thirtieth of an inch in 
thickness, which must aid the animal greatly in adhesion, by filling 
up all the little crevices and excluding the air.” [J. P. c.] 
Abundant everywhere in Orange Harbour. 
