APPENDIX. 527 
demonstrated that the organs of the two objects are absolutely 
identical in every point as regards anatomical structure. The 
variations, except in one pomt, belong to the shells; the 
M. brachystoma is rather more slender, with stronger strie, 
more gradually taper, a little flatter on the top of the volutions, 
and the animal has the flake-white markings on the foot much 
more densely distributed than in its hitherto considered con- 
gener, the WM. Ginannianus. But under the circumstances of 
the identity of the organs of the two, and the quality of the 
markings being undistinguishable under the microscope, I 
shall account for the numerical difference of the spots by the 
ungallant assertion of the schools, that the masculine is more 
worthy than the femimine; and as it is well known that in 
many animals of.the same species the colours and markings of 
the two sexes vary greatly, they may do so here. I have 
therefore adopted the opinion, that the more slender shell, 
termed “ brachystoma,” is the male, and the “ Ginannianus ” 
the female. 
M. Philippi’s appellations for the so-called species are con- 
temporaneous ; I therefore propose “brachystoma” for this 
animal, as being the more significant, receiving the “ Ginanni- 
anus” as its synonym. 
Though the M. nebula has close relations with this animal, 
T think it distinct. 
Morex purrvurevs, Montagu.—(P. 499.) 
Mangelia purpurea, Brit. Moll. ii. p. 465, pl. 113. f. 3, 4, 5. 
We beg that the following notes of this species may be 
substituted for those quoted. 
Shell. —'The specimen observed presented eight spiral, 
moderately taper, dark purplish-brown, closely cancellated 
volutions, of about half an inch in length in the whole, with 
a narrow white band in the centre of the body-whorl. Ex- 
amples of larger growth inhabit the corallme zone; these 
are near an inch long, composed of ten turns, which vary m 
colour from red-brown to pale drab. At the upper angle of 
the aperture is a distinct sinus or emargination; the margin 
