1804. Carlisle, in Phil. Trans., XCV. 12. The horns and cuticular coverings, are all of them extra-vascular.
1854. Woodward, Mollusca (1856), 42. Being extra-vascular it [the shell] has no inherent power of repair. (Carpenter.)
1866. Huxley, Physiol., ii. (1869), 26. There are certain parts which are said to be extra-vascular or non-vascular.