Further Remarks on the Relationship of the Xiphosura to the Eurypterida and to the Trilobita and Arachnida

Abstract

I had, on a former occasion (November 21, 1866), the honour to communicate a paper to this Society “On some points in the structure of the Xiphosura having reference to their relationship with the Eurypterida”, in which were discussed the grounds for the union of these two suborders (afterwards dealt with in greater detail in the monograph of the Merostomata in the Palæontographical Society9s publications for 1866). I therefore venture to think it may not be considered inappropriate if I bring the subject again under your consideration after an interval of five years, during which time some considerable additions have been made to our knowledge of this group. The papers to which I shall have occasion especially to refer are the following:— 1.“On a New Limuloid Crustacean (<i>Neolimulus falcatus</i>) from the Upper Silurian of Lesmahagow, Lanarkshire.” By H. Woodward. (Geol. Mag. 1868, vol. v. pl. i. fig. 1, p. 1.) 2.“On some new Species of Crustacea from the Upper Silurian Rocks of Lanarkshire, and further Observations on the Structure of <i>Pterygotus</i>.” By H. Woodward. (Quart. Journ. Geol. Soc. 1868, vol. xxiv. pis. ix. &amp; x., p. 289.) 3.“Notes on some Specimens of Lower Silurian Trilobites.” By E. Billings, F.G.S. (Quart. Journ. Geol. Soc. 1870, vol. xxvi. pls. xxi. &amp; xxii., p. 479.) 4.“Note on the palpus and other Appendages of <i>Asaphus</i> from the Trenton Limestone, in the British Museum.” By Henry Woodward. (Quart. Journ. Soc. 1870, vol. xxvi. p. 486.)