446 Mr. W. Clark on the Pfuenomena of the XXX VII. — On the Phenomena of the Reproduction of the Chitons. By William Clark, Esq. To the Editors of the Annals of Natural History. Gentlemen, Norfolk Crescent, Bath, November 1855. The Chitons have long been a source of difficulty to naturalists with respect to systematic position; the most distinguished names, Cuvier, Blainville, Milne-Edwards, and Prof. Forbes, are at variance on this point, which to the present time has not received a satisfactory solution. Cuvier alone considers them true Mollusca ; Blainville refers them to the Annelidan Articu-lata y Forbes speaks doubtingly ; and Milne-Edwards admits that they are Gasteropoda, but hesitates to acknowledge them Mol-lusca. I trust the following observations, though not so complete as I could wish, will throw some light on their reproductive statiis and natural position. The present paper has originated in a suggestion of the late Prof. Forbes and Mr. Hanley, who in their ^ British Mollusca,^ vol. ii. p. 390, "trust that some active observer resident by the coast will occupy himself with studying the development of the Chitons, and endeavour to ascertain the form they assume in their larval condition. Whoever does so will make an important discovery, and do more towards fixing the true position of these anomalous creatures than all cabinet examinations of them have yet enabled us to effect." And I have stated in my late work on the ' British Marine Testaceous Mollusca,' p. 248, " that I propose, if practicable, to carry out this idea, though the at-tempt will be attended with uncertainties which need not at present be alluded to.'' Chiton cinereus, Linnseus. Chiton cinereus, Brit. Moll. vol. ii. p. 402. Chiton marginatus, variorum. On the 23rd July 1855, I obtained several examples of the above species fixed on small pebbles from their natural habitat ; these were carefully removed into saucers of sea-water and sedulously examined every hour for many following days. In the afternoon of the day of capture my attention was suddenly attracted by observing one of the animals in the act of dis-charging ova — not in volleys, but by one or two at every second for at least 15 minutes, forming a batch of 1300 to 1500; there were a thousand or more that remained in the ovarium, perhaps not sufficiently maturated for parturition ; they were pale yel-
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