Hyde. — Camarophorella 
EXPLANATION OF PLATES. 
PLATE 6. 
Athyris. 
Fig. 1. Diagram of the structure of the brachidium in Athyris. After Hall 
and Clarke, '95, p. 86. o, primary lamellae of spiral coil; a', 
secondary lamellae; a", umbonal blades; h, accessory lamellae; 
c, crura; e, lateral branches of loop; /, arms of loop; I, loop; 
TO, fimbriated extension of saddle; n, fimbriae on outer margin 
of lamellae; s, saddle; /, stem of loop; .r, spiral coil. 
Camaroj)horella mutabilis. 
Fig. 2. Structure of brachidium in Camarophorella; lettering as in figure 
1, and in addition: u, A-shaped notch, the apex of which rests 
on the niedian septum of the brachial valve. 
Fig. 3. Supposed method of attachment of the primary lamella to the crus, 
the edge of the ribbon resting in the grooved anterior surface of 
the flattened crus. Viewed from side. 
Fig. 4. Inner surface of the end of the primary lamellae at the point of its 
attachment to the crura, showing the unfractui-ed edge but 
slightly recurved tip. 
Fig. 5. Lateral view of an internal mold of a young specimen showing 
position and size of the plate between the inner surface of valve 
and spondylium at this stage, ;:). This is the specimen illustrated 
in figure 51 (pi. 10). X 4. 
Fig. 6. Similar vieW' of another specimen. X 4. 
Figs. 7, 8. Brachial and lateral views of a small specimen showing the reduc- 
tion in size of this plate and its relative movement tow'ard the 
hinge line, p. The position is such that it is not visible in the 
lateral view. This figure illustrates also a specimen of the elong- 
ate tj'pe. Natural size. 
Figs. 9, 10. Two views of a large specimen showing extreme reduction of 
the plate between the spondylium and inner surface of the valve, 
p. Natural size. 
Figs. 11, 12. Two view^s of a specimen showing reduction and movement of 
plate p, but not to such an extent as in figures 7 and 8. These 
two specimens represent the extremes of the elongate and the 
transverse tj^pes. Natural size. 
