PULMONATA. 139 
of the characters distinguishing this new species ; but it is not improbable that Dr. Bey- 
rich may have associated specimens of 7. contabulata with the true AZ. hordeola. 
It is always hazardous, without the assistance to be derived from actual specimens; 
to express an opinion on questions of identity; but the figure given by Dr. Beyrich 
does not convey to my mind an idea of J. edurnea; the spire seems to be shorter 
and thicker, the apex to be more obtuse ; the aperture to be shorter, less wide in front, 
less narrow behind; the outer lip is represented without the posterior sinus, and the 
folds on the columella appear to be more oblique. The figure agrees much better with 
M. contabulata, to which species, if it had been published, the German shell would 
more probably have been referred. 
The present species appears to be confined to the older tertiary formations ; 
the shells from Dax, and the neighbourhood of Bourdeaux, referred to it by Grateloup, 
belong to a different species, which D’Orbigny has named J/. sub-eburnea; as do those 
from Turin, described by Sismonda, and to which Michelotti has given the name, 
M. Taurinensis. 
Size, of the specimen figured, which forms part of Mr. D’Urban’s collection, is, 
axis, 3-10ths of an inch; diameter, half the length of the axis. The French speci- 
mens are frequently much larger. 
Localities—Bracklesham Bay, where it is very rare. French: Grignon, Parnes, 
Courtagnon, Ermenonville, Acy, le Tombray (fide D’Orb.). Jtalian: Ronea, Val 
Sangonini (fide Brogn.) German: Osterweddingen in Magdeburg? (fide Beyr.) 
No. 81. MARGINELLA BIFIDO-PLICATA. Charlesworth. Tab. XVIII, figs. 2 a—y. 
M. testa minimd, ovato-globosd, ad basin vie emarginatd; spird conicd, brevi, apice sub- 
obtuso ; anfractibus converis: aperturd angustd, longitudine spiram paulo superanti ; labro 
crassissimo, compresso, extis marginato, intis acuto, postice profundée emarginato; columella 
quadriplicatd, plicis tribus posticis bifidis, pene transversis ; plicd anteriori acutd, obliqud. 
Shell very small, roundedly ovate, with a short, conical spire and a bluntish apex: 
aperture narrow, a little longer than the spire, with the margins nearly parallel : outer 
lip much thickened, presenting a prominent border along the outer margin, a sharp 
edge inwards, and a deep sinus near the suture ; columella with four folds, of which 
the anterior one is sharp and very oblique, and the remaining three thick, bifid, and 
nearly transverse. 
This marginella approaches very closely to a species from the Paris Basin, not yet 
described, but to which M. Deshayes has given the name JZ. columbellina, and a com- 
parison with a longer series of that species than I possess, may eventually establish the 
identity. It appears, however, to be a broader and more ventricose shell, having a 
