A Monograph on the Sub-class Cirripedia · Charles Darwin
PLATE 14.
_Genera_--CREUSIA AND CHELONOBIA. 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.
Text from Project Gutenberg, public domain in the United States.