188 GASTEROPODA OF THE INFERIOR OOLITE. 
subconcave, sutural sulcus wide. The ornaments undergo considerable modi- 
fication. Apical whorls unknown. ‘Towards the middle of the spire the posterior 
margin of each whorl carries a single row of roundish tubercles, below which is a 
slight constriction, and then a convex zone made up of undulating spirals 
decussating with short cost. In the anterior whorls a considerable change takes 
place; the whorls become concave, and instead of costz a single row of tubercles 
occurs at each extremity, the spiral ornaments remaining the same. 
The body-whorl is relatively small, angular, and with a base which is depressed 
and slightly excavated towards the centre. Aperture restricted anteriorly, sub- 
oblong, columella short, outer lip slightly constricted. 
Relations and Distribution—This is the most cylindrical of the several forms 
described from the Inferior Oolite. It also differs considerably in the details of 
ornamentation from C. Bajocensis. In other respects it must be regarded as 
closely approximating to that species. When comparing it with species from the 
Lias of Sicily it seems to resemble Cerithinella elegans, Gemm. (op. cit., p. 285, 
pl. 23, fig. 34). Fig. 4a represents the type-specimen obtained by Mr. Brodie 
from the Leckhampton Freestones. Fig. 45 represents either a variety, or the 
earlier stage before the whorls become concave; it was collected by Lycett from 
the Inferior Oolite of Nailsworth. : 
Fig. 5 represents the anterior whorls of a larger shell, somewhat modified by 
mineralization from the Murchisone-zone of Stoford. This last may represent 
the maturer condition of C. Brodiei; or, what is more probable, of C. Bajocensis, 
var. drosera. 
PSEUDALARIA, genus novum. 
Testd subelongata, conicd, acutd. Anfractibus spiraliter striatis, in medio vel sub 
medio carinatis, carinis sepe crenulatis ; ultimo anfractu bicarinato. Apertura 
quadratd, antice et postice subcanaliculatd ; labro dextro sinuato. 
The above generic diagnosis is practically that given by Deslongchamps in 
describing Turritella unicarinata (vol. cit., p. 151, pl. xi, fig. 68), said to occur in 
the Oxford Clay of Dives. Turritella Guerrei, Héb. and Desl. (op. cit., p. 46, 
pl. vi, fig. 6), from the Callovian of Montreuil-Bellay, is a somewhat narrower form. 
Cossmann (op. cit., p. 229, pl. v, fig. 15) describes a still narrower variety of 7’ 
Guerrei from the Bathonian of Le Wast. 
The latter author observes that 7’. Guerrei might almost as well be an Alaria 
as a Turvritella, since the double keel reminds us so much of the former, though 
the form of the aperture removes it completely from Alaria. He suggests a 
change of genus. Undoubtedly the spire has a remarkable resemblance to some 
