48 Mr. W. Clark on the lanthinse, Scalarise, 



aperture in lanthina, by its columellar elongation and canaliferous 

 tendency, shows that it is in a state of transition, and the short 

 neck and head, with the retractile rostrum, point out that in the 

 soft parts there are also the elements of transition, 



lanthina communis, Lamarck. 



Animal inhabiting a spiral, subglobose, bluish-white or lilac- 

 coloured shell of four tumid volutions and a minute reflexed 

 apex. Mantle lax, swelling beyond the margin of the aperture 

 and forming an incipient canal. The neck and head are very shoi't, 

 but capable of evolving an inflated retractile proboscis, which 

 has been mistaken for the head itself; it is armed, as in the Mu- 

 rices, with corneous plates and the usual short spiny tongue. 

 Tentacula shoi-t, conical, pointed, with deeply cloven offsets of 

 half their length; but the eyes are obsolete, probably being use- 

 less, as the animal floats with the shell downwards and the 

 foot to the skies. Foot truncate anteally ; auricled at the ex- 

 ternal 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 \he 

 matrix; it exudes from the collar and surface of the body a 

 purple liquid. There are two branchial plumes, one with a 

 double row of strands, and there are the rudiments of mucous 

 fillets ; in fact, all the organs resemble those of Murex. I should 

 rejoice to review this species, as my examples, though alive, 

 were torpid from the effect of the agitation of the tides on the 

 shores, consequently there was no adequate exertion of their 

 organs. 



I beg malacologists to lose no opportunity of rigoroiisly exa- 

 mining 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 Muricidce. M. Cuvier 

 insists again and again that it is retractile, asssimilating it to that 

 organ in the Buccinum undatum, which he has so elaborately 

 described, and stating that when he treats of that muricidal 

 animal, the mechanism of lanthina by comparison will be better 

 appreciated. Therefore, after M. Cuvier's particular and minute 

 account, that the proboscis in this species is a great and inflated, 

 though short muzzle, that can be retracted within the buccal 

 sheath, we must bow to such high authority ; but independent 

 of this fact, there are other characters which sufficiently declare 

 that this extraordinary animal can have no other allocation than 

 in the vicinity of the Muricida. 



This is the only species I have seen alive ; one or two other 



