TURRITELLA. 
229 
number of spirals above tbe keel is only five. Other specimens present trifling 
differences. 
The base is nearly flat and spirally striated ; columella short, aperture sub- 
quadrate and restricted. (N.B. — The columellar lip is too much rounded in the 
figure.) 
Relations and Distribution. — This species stands out very prominently from the 
other Turritellids of the Inferior Oolite, being distinguished by the conical form of 
the whorls and by the prominence of the single carina near the base of each whorl. 
T. Dorsetensis differs from the T. Schlumbergeri, Bug. Desk, in its richer ornamen- 
tation, and in having, in the adult shells, a greater number of spirals, but, above 
all, in the more median position of the keel. In the variety from the Murchisonse- 
zone of Bradford Abbas (fig. 1 b) this difference in the position of the keel is at 
its maximum. 
T. Dorsetensis occurs rarely in the Irony-nodule Bed of Burton Bradstock, 
and in the Lower Division of the Inferior Oolite of Bradford Abbas, where it is 
also rare. A small fragment has been found in the freestones of the Inferior 
Oolite near Cheltenham (Brodie Collection). 
166. Tureitella cf. Schlumbergeri, Eugene Deslong champs, 1863 — 66. Not 
figured. 
1863 — 69. Txjebitella Schlxjmbeegeei, Eugene Deslongchamps. Notes Paleonto- 
logiques, p. 93, pi. viii, figs. 8 a, 
8d, 8 c. 
The late Prof. Eugene Deslongchamps founded his species upon four speci- 
mens belonging to the Faculty of Sciences at Caen procured by Mons. Schlumberger 
from the Inferior Oolite of the Meurthe. None are quoted from the “ Oolite 
ferrugineuse ” of Normandy. 
This species has considerable affinity with T. Dorsetensis, but the keel is 
represented as being less prominent, and, moreover, is placed much nearer the 
base of the whorls, so that only one spiral instead of four occupies the space 
between the keel and the suture. 
One specimen, answering fairly well to the figures and description in the ‘ Notes 
paleontologiques,’ is in my possession from the Inferior Oolite of Dorsetshire. It 
is interesting to make this identification, since the fossils from the so-called 
Sowerbyi-hedi of the Meurthe seem to possess considerable afl&nity with those from 
the concavus-hedi of Bradford Abbas. Possibly T. Dorsetensis might be regarded 
as a marked local variety of T. Schlumbergeri. 
