FOSSIL CIRRIPEDIA. 
Fig. 8a, Coronula barbara, rostrum, external view ; nat. size. 
84, m i viewed internally; twiceMiat. sIZze. ; 
8c, i oe lateral compartment, internal view. . 
Sd, i Fy; internal view, much enlarged, of small portion of basal margin 
of folded wall. 
8e, ie - external view, greatly enlarged, of small portion of surface of 
folded walls, near the basal margin; (7 r) the transverse 
ridges of growth. 
The following letters of reference apply to all the figures of Coronula : 
a, sheath marked transversely in the upper part by the attachment of the 
opercular membrane. 
a’, ala 
b, furrow on each side of (a), receiving the edge of the thick ala of the 
adjoining lateral compartment. 
c, special plate, on which the ala rests. 
d, radius, on the edge it may be just seen to consist of an outer layer (the 
normal radius), and a much thicker inner part (the pseudo or com- 
plementary radius) formed of oblique denticulated septa. 
e ee’, basal edge of wall, which from its commencement at e, or e’, can be 
followed, folding up to near the basal edge of the sheath, to its 
termination at e” or e. 
J f, serrated lines of junction between the folds of the wall. 
Fig. 9a, Verruca Stromia, much enlarged, engraved from a recent specimen, only certain 
valves having been found fossil. 
94, % fixed scutum and tergum, internal views. ‘The following 
letters apply to both these figures : 
A, rostrum. 
B, carina. 
s, moveable scutum, s’, scutum fixed and modified so as to form part of shell. 
T, moveable tergum, 1’, tergum fixed, forming part of shell. 
In s, and s’, a is the occludent margin; 8, the basal margin ; m, the plate 
to which the adductor muscle is fixed. 
In s and s’, the tergal margin is marked by small dashes; (’) being the 
upper articular ridge, and ('’) the second or lower articular ridge: in 
s’ () is called the parietal portion of the valve. 
In Tt and 1’, the scutal margin is marked by small dashes ; (’) being the first 
and upper articular ridge, hardly distinct from the occludent margin, 
and called in 1’ the occludent rim; () is the second or middle, and 
(") the lower or third articular ridge, called in 1’ the parietal portion of 
the valve: 2 is the carinal margin, called in 1’ the carinal rim, and z 
the basal margin. 
Fig. 10a, Verruca prisca, five times nat. size. 
LOS N06, scutum and tergum, external views; engraved from a Belgian 
Cretacean specimen, the opercular valves not having been 
found in England. 
