ALARIA. 133 
describes three varieties of Al. Lovieri. His third variety, which occurs in the 
“ Oolithe ferrugineuse ” of Bayeux (op. cit., pl. ii, figs. 12—14, and pl. iii, figs. 11, 
12), might be expected to have most resemblance to our Dorsetshire specimens. 
There are differences in the Dorset-beds but they do not correspond in all cases 
to the differences indicated by Piette. Viewed broadly we may say that the 
trifida-group is represented in the Inferior Oolite by a series of fossils which in 
France are recognised for the most part as Al. Lorieri, and in Germany as 
Al. (Chenopus) Philippi. ach of these has its own set of synonyms, and some 
English paleontologists would designate the whole as Alaria trifida. 
Without doubt the Burton-Bradstock fossils must be regarded as representing 
the Al. Lorieri of common repute, though possibly not exactly the Al. Lorieri 
of D’Orbigny. Three varieties are shown in the accompanying plate, and these 
I proceed to describe. 
Vir Al (igs 6 a46-6, 6'¢:) 
Description : 
Length : : ‘ 5 20 mm. 
Width of last whorl to height of shell . 45:100 
Spiral angle ; . : W808 
Shell fusiform, sub-turrited. Whorls nine; apex moderately blunt; apical 
whorls tumid without keel or ornament; the five succeeding whorls of the spire 
are strongly carinate; the carina is median, and in well-preserved specimens is 
seen to be characterised by a furrow. (This is one of the distinctive features of 
Al. Lorieri according to Piette). There are no longitudinal ornaments, but the 
spiral lines are regular and conspicuous, being most numerous on the posterior 
area of each whorl; in the anterior area is a sulcus immediately above the suture, 
and in the middle of this sulcus is a fine thread-like line, most obvious on the last 
three whorls; a rim is exposed at the base of the lower whorls, and the suture 
rather gapes in consequence. The body-whorl is strongly bicarinate, the posterior 
keel, representing the median carina of the spire-whorls, beg the most salient. 
It gives rise to the posterior digitation (fig. 6 6) which rapidly attenuates in 
describing a curve, whose centre is a point some little way beyond the apex of the 
shell. The wing is slightly palmate, the intercarinal space being slightly excavated 
and spirally striated. The anterior digitation, although arising from the least 
salient keel, becomes wide and bayonet-shaped for a short distance, and after 
developing a broad, tongue-like process, curves slightly upwards to its blunt 
termination (fig. 6 ). 
