GASTEROPODA. 17 
extremity ; the aperture is oblique, contracted at the base, sometimes slightly channelled, 
in other instances entire and rounded; the outer lip is much curved and thin. Young 
specimens are less subulate, but the apex is delicately pointed, the volutions are more flat- 
tened and narrow, the sutures being less strongly marked; the latter two or three volu- 
tions in adult specimens are more inflated, and they acquire at the base a rudimentary 
umbilical groove. 
It is nearly allied to Mula nudiformis, Piette (« Bull. de la Soc. Géol. Fr.,’ 1857, 
pl. 6, figs. 4, 5), from the Great Oolite of Rumigny, Eparcy, Poix, But, &.; but, judging 
from the figures of M. Piette, his species has a shorter spire, with less strongly impressed 
sutures, and the last two volutions are more lengthened and cylindrical. Fibula 
Chemnitzia phasianoides, which has the spine similarly subulate, has the volutions more 
flattened, and the sutures much less impressed; other recognised species are more 
lengthened, with flattened volutions. 
Geological Position and Localities. Fibula variata has occurred rarely in the Great 
Oolite of Minchinhampton, and more commonly in the same formation at Kirklington, 
Oxon., from which place Mr. Whiteaves has kindly forwarded specimens. Examples are 
deposited in the British Museum, the Woodwardian Museum, Cambridge, in the collection 
of Mr. Whiteaves, of Oxford, and in that of the author at Scarborough. 
Fisuta rvLimow:s, Whiteaves, sp. Tab. XXXI, fig. 5. 
CHEMNITZIA BULIMOIDES, Whiteaves. MSS., 1859. 
Testa turriculata, elongata, spira apice acuto, anfractibus (circa 12) angustis, convexis 
superne vitta cingenda, suturis valde constrictis, ultimo anfractu rotundo ; apertura obliqua, 
bast angusté subsinuato, columella umbilico rudimento ; labro externo arcuato ; anfractibus 
costis obliquis obscuris irregularibus. 
Shell turreted, elongated, acute ; spire with about 12 volutions, narrow, convex towards 
their lower parts, and encircled with a narrow band at their upper borders; the sutures 
are deeply impressed; the last volution moderately large and rounded; the aperture is 
lengthened, oblique, narrow, and sinuated at the base; there is also a rudimentary um- 
bilical groove; the outer lip is much arched; the surface has irregular, oblique, obscure 
coste, which resemble lines of growth in the latter volutions. 
Compared with /éula variata, this species is more subulate, with a shorter last volu- 
tion; the encircling band upon the upper border of each volution, the oblique coste, and 
the convexity of the lower part of each volution, are also distinguishing features. //du/a 
undulosa, Piette, is more nearly allied to it, but the volutions are less narrow and more 
flattened or destitute of the swelling of the lower portions of the volutions which is a 
conspicuous feature in /. ewlimoides. The height of each volution is equal to half of its 
opposite diameter. 
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