Paper, 'On the nervous system of the Crinoidea' by William B [Benjamin] Carpenter Carpenter writes: 'In a memoir “On the Structure, Physiology, and Development of Antedon (Comatula, Lamk.) rosacea”, presented to the Royal Society in 1865 [published in the Proceedings of the Royal Society, volume 24], I stated that I had ascertained that the cord lying between the two principal canals in the arms of Crinoidea which had been regarded by Professor J Müller as a nerve, really belongs to the reproductive apparatus; and further, that I had been led to regard as a nerve-trunk the solid cord which traverses the axial canal of each calcareous segment of the rays and arms, through finding that this cord gives off a regular system of branching fibres to the muscular bundles which intervene between the calcareous segments, and which flex the arms by their contraction. In a further communication on this subject made to the Royal Society at the beginning of 1876 ['On the structure, physiology, and development of Antedon (Comatula, Lamk.) rosaceus', Proceedings of the Royal Society, volume 24], I supported this view by experimental evidence; showing that in an eviscerated specimen of Antedon, irritation of the quinquelocular organ (contained in the centro-dorsal basin) from the walls of which the radial cords proceed, produces a sudden and simultaneous contraction of the flexor muscles of the arms, similar to that which I had mentioned in my memoir as resulting in the natural condition of the animal from irritation of its oral pinnules.' Annotations in pencil and ink. Subject: Zoology Received 20 May 1884. Read 29 May 1884. A version of this paper was published in volume 37 of the Proceedings of the Royal Society as 'On the nervous system of the Crinoidea'. 1884