- Fig. 6 i, 6 k, 6 l, Creusia spinulosa, var. 4, 6 i, tergum, external view; 6 k, the same, from another individual; 6 l, the same, internal view.
- 6 m, Creusia spinulosa, var. 5, tergum, external view.
- 6 n, 6 o, 6 p, 6 q, Creusia spinulosa, var. 6, 6 n, scutum, external view of; 6 o, tergum of same individual, external view of; 6 p, scutum of another individual, external view of; 6 q, tergum of latter, external view of.
- 6 r, Creusia spinulosa, var. 7, scutum, internal view of.
- 6 s, Creusia spinulosa, var. 9, scutum and tergum, calcified together, external view.
- 6 t, Creusia spinulosa, var. 10, scutum and tergum, calcified together, external view.
- 6 U, Creusia spinulosa, var. 11, shell seen from above; 6 u, scutum and tergum, calcified together, external view.
- Fig. 1 a, Chelonobia testudinaria, shell seen from above; a specimen
has been chosen, with some of the radii smooth, and others
more or less notched; 1 b, scutum, internal view of; 1 c, tergum, internal view of; 1 d, scutum and tergum, joined together, external view of.
- 2, Chelonobia caretta, shell seen from above.
- 3 a, Chelonobia patula, shell seen from above; 3 b, tergum, external view of.
- 4, Carina of Chelonobia patula, seen from within; a a, outer lamina of wall, joined by the longitudinal septa to b, the inner lamina; e c e, sheath, descending to the base of shell, with the middle part largely hollowed out; the
upper part of the sheath, above d d, is transversely marked by the lines of attachment of the opercular membrane; d, d, alæ.
- 5, View of the edge of the radius of the rostrum of Chelonobia testudinaria.
- a, a, inner portion of radius.
- b, thick outer lamina of the radius, transversely pitted; beneath
this pitted portion, which forms only the outer surface of the radius, and distinct from the
inner portion a, the arborescent and dentated sutural edges of this outer lamina are seen.
- c, outer lamina of wall of compartment.
- d, the exterior septum, connecting the outer lamina of the wall to the inner lamina;
the basal edge of the inner lamina of the wall is seen beneath and without the lower
end of the inner portion (a) of the radius.