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. 



/. communis, Brit. Moll. ii. p. 549, pi. 69. f . 6, 7 ; and iv. p. 260, 



pi. 133. f.l. 

 /. pallida, Brit. Moll. ii. p. 553, pi. 69. f. 10, 1 1. 



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 spiny 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 

 tapering 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 Murex. 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 points 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 Muricidae. 

 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 



