EMARGINULA. 253 
base with a few minute brown points; the orifice is radiated 
sparingly with pale brown lines; the tentacula are white, 
strong and short, slightly tapering, with the eyes at the ex- 
ternal bases scarcely raised. The buccal mass consists of the 
usual fleshy palate and corneous plates, through which a 
spinous lingual riband passes into the cesophagus and stomach. 
The foot is an elongated oval, which in full extension exceeds 
the length of the shell; its colour on the under part varies 
from yellowish-white to an intenser yellow; on the upper, it 
is aspersed with brown sand-lke dots, mixed with yellow 
nearer the margin. The branchial apparatus consists of two 
pale brown, rather long, transversely striated plumes, each 
folded on itself; these originate in a cavity of the neck, and 
proceed on each side of it to form near the front a pointed 
termination; it is probable they receive water both from the 
basal cavity and vertical fissure. The intestine as soon as it 
emerges from the stomach, having run some way as duo- 
denum, is doubled over the centre of the liver, which is mixed 
up with the ovarium, and passes as a simple rectum girded 
by the heart and auricles to its debouchure, the vertical 
fissure, between the pedicles of the branchiz. 
These animals are not uncommon on the littoral rocks, and 
are also taken on the marine masses of the coralline zone. 
EMARGINULA, Lamarck. 
E. reticutata, Sowerby et Auctorum. 
E. reticulata, Brit. Moll. ii. p. 477, pl. 63. f. 1 (as Miilleri). 
E. rosea, Bell. 
—_——., Brit. Moll. ii. p. 479, pl. 63. f. 3. 
Animal inhabiting a white, strong, reticulated, subsymme- 
trical, conical, emarginate shell; the vertex is slightly coiled 
posteriorly, and lies laterally in very young specimens, but 
when adult it becomes blunt and obliterated; this cireum- 
stance, with the rosy tint in fresh examples, have converted a 
unique British species into two. The mantle is white, slightly 
dentated at the margin; the head is a short, smooth, pale 
yellow muzzle, with the disk of the mouth rayed with flake- 
