Keywords: Origin of Vertebrates Fig 144.png Fig 144 ”A A Goblet from one of the Branchial Sense-organs of Limulus ch t chitinous tubule ; B Surface View of a Portion of a Branchial Sense-Organ 1908 The Origin of Vertebrates https //archive org/details/originofvertebra1908gask Walter Holbrook Gaskell PD-old-auto-1923 1914 Origin of Vertebrates book Limulus polyphemus anatomy |