11. Radula with tricuspid central tooth with square basal plate , as large as the bicuspid laterals, the marginals multicuspid. 12. In the first marginal tooth, the main cusp is less symmetrical and the basal plate is less prominently developed. 13. The tendrils will later form the basal plate of the adult sponge that firmly anchors the animal to the reef. 14. The ventral part of the neural tube is called the basal plate ; the dorsal part is called the alar plate. 15. The optical vesicle ( which eventually become the optic nerve, retina and iris ) forms at the basal plate of the prosencephalon. 16. The root cluster attached to the basal plate of the bulb is the only part not typically considered palatable in any form. 17. The basal plate is used to scrape smaller organisms off of the grains of sand that make up their anoxic seabed mud habitat. 18. This dorsal spine is fitted over a long basal plate and articulating at its base with the apex of a high triangular fin. 19. True twin-scaling involves further subdivision of the chips to create pairs of scales, joined together by a small part of the basal plate . 20. The alar plate of the prosencephalon expands to form the cerebral hemispheres ( the telencephalon ) whilst its basal plate becomes the diencephalon.
