IANTHINA. 459 
the short neck and head, with the retractile rostrum, point 
out that in the soft parts there are also the elements of 
transition. 
I. communis, Lamarck. 
I. communis, Brit. Moll. ii. p.549, pl. 69. f.6, 7; and iv. p. 260, 
pl. 133. f. 1. 
I, pallida, Brit. Moll. ii. p. 553, pl. 69. f. 10, 11. 
Animal inhabiting a spiral, subglobose, bluish-white or 
lilac-coloured shell of four tumid volutions and a minute re- 
flexed apex. Mantle lax, swelling beyond the margin of the 
aperture and forming an incipient canal. The neck and head 
are very short, but capable of evolving an inflated, retractile 
proboscis, which has been mistaken for the head itself; it is 
armed, as in the Murices, with corneous plates and the usual 
short spmy tongue. Tentacula short, conical, pointed, with 
deeply cloven offsets of half their length ; but the eyes are obso- 
lete, probably being useless, as the animal floats with the shell 
downwards and the foot to the skies. Foot truncate anteally ; 
auricled at the external angles, moderately long, gradually 
tapermg to a point. On the under part, the animal in the 
genial season deposits the vesicular mass containing the ova 
and pulli, ejected from the matrix; it exudes from the collar 
and surface of the body a purple liquid. There are two bran- 
chial plumes, one with a double row of strands ; there are also 
the rudiments of mucous fillets; in fact, all the organs re- 
semble those of Murer. I should rejoice to review this spe- 
cies, as my examples, though alive, were torpid from the effect 
of the agitation of the tides on the shores, consequently there 
was no adequate protrusion of their organs. 
I beg malacologists to lose no opportunity of rigorously 
examining these animals, as there are still pomts in their 
structure on which it would be desirable to have further 
information ; amongst them the constitution of the proboscis, 
whether it be strictly the proboscis retractilis of the Muricide. 
M. Cuvier insists again and again that it is retractile, assimi- 
lating it to that organ in the Buccinum undatum, which he 
has so elaborately described, and stating that when he treats 
