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 oasophagus 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-like 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 branchiae. 



These animals are not uncommon on the littoral rocks, and 

 are also taken on the marine masses of the coralline zone. 



EMARGINULA, Lamarck. 

 E. RETICULATA, Sowerby et Auctorum. 



E. reticulata, Brit. Moll. ii. p. 477, pi. 63. f. 1 (as Miilleri). 

 E. rosea, Bell. 



, Brit. Moll. ii. p. 479, pi. 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 circum- 

 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- 



