ALATID As. 473 
of retractile. It is simply cloven as in Janthina and Natica, 
the cleft being rather within the margin of the buccal disk, 
and provided with the precise attenuated corneous plates and 
short tongue of the typical proboscis of the Murex undatus. 
But if malacologists think that what I have stated is not 
tenable, I will, though my opinion is fixed, abandon this 
view; I can well afford to do so, as I have in the shell, 
the animal, and its habitudes, more than sufficient to con- 
vince naturalists of the true position of the Rostellaria pes 
pelecani. As regards the shell, the alated processes are 
altogether analogous to the exotic Rostellarie and Strombide, 
which no one disputes being peculiar developments of the 
Muricide. The canal of the shell also at the outer lip 
side of the beak, or axial process, if viewed properly, that 
is, with the edge to the observer, is as well marked as in 
those genera; and in adult shells the outer lip has a long 
vertical row of the same characteristic plice that are seen in 
the Marginella levis, the only other British mollusk I can 
recollect that has them,—another strong, I may say con- 
vineing, proof that the so-called Aporrhais pes pelecani is a 
Muricidal animal. 
As regards the animal, the operculum is absolutely Muri- 
eidal, and I challenge the most acute observer to distinguish 
between it and that of a Murex Turtoni of the same size. 
As for the flimsy objection of the pedicles of the Strombide 
bemg peculiar, they are nothing more than typical specific 
variations. 
I will now allude to the locomotive habitudes of the 
“ Rostellaria pes pelecani”’; they are most singular, and the 
concordance in that respect with the exotic Strombide men- 
tioned by Quoy and Gaimard, is perfectly irresistible as to 
family identity. M. Deshayes, speaking of these gentlemen, 
observes :— 
“ On sait depuis eux que le pied de ces mollusques ”’ (Roste/- 
laria and Strombus) “west plus propre a la reptation, et que 
Panimal, pour changer de place, est obligé de sauter, en ap- 
puyant sur ’extrémité du pied qui porte l’opercule.” 
