Folliculinids of Ago Bay, Japan — Matthews 
239 
l 1 
I m m 
Fig. 7. Lagotia expansa var. depressa. 
A, a, Operculum of Spirorbis sp.; b, calcareous shell. 
B, Ventral view showing: a, delicate flare of collar; 
lorica ; e, nucleus ; f, non-spatulate foot. 
C, Ventro-lateral view of same structures. 
75|i to 48p (Fig. 9 A, d ). Only 4 or 5 spiral 
whorls (c) are present which mark off the 
neck region (d) from the rest of the lorica (/). 
The overall length of the lorica is 2 5 Op of 
which the neck usually makes up about half. 
No valves are present. 
In every instance, only the left peristomal 
I 1 
I 50 p 
b, longitudinal stripes; c, peristomal lobe; d, flattened 
lobe ( a ) is present This measures about 125p 
long when fully extended and varies from 12 to 
25p in width. There are no peristomal projec- 
tions. In the contracted animal (Fig. S>B) the 
peristomal lobe ( a ) is often curved. If the 
condition of but one peristomal lobe proves to 
be only a transitional stage, then these specimens 
