III.—Upper Cretaceous Terebelloids from England

Abstract

The tubes formed of fish-debris, found throughout the Chalk of England, described by Mantell (1822) as Murœna(?) lewesiensis, referred by L. Agassiz (1844) to Dercetis elongatus, and placed among Annelida Tubicola as Terebella lewesiensis by William Davies (1879), are here described with more precise detail and retained in the position assigned to them by Davies. A diagnosis is provided and a holotype selected.A specimen from the Gault, of similar nature but larger, is made the type of a new species, ‘Terebella’ lutensis (Fig. 6).Similar tubes from the Cenomanian, built of Conifer debris and Echinoderm debris, are described, and the question whether these differences of composition indicate a difference of species is discussed, but left open for the evidence of further material. Such tubes may for the present be known as ‘Terebella’ cf. lewesiensis (Figs. 7, 8).Tubes without extraneous building material and with a cancellar ornament are also found in the Cretaceous rocks of England, and some were referred to Terebella lewesiensis by Davies. All those from the Chalk are here separated as ‘Terebella’ cancellata, n.sp. (Figs. 3–5).Two tubes made of mud bricks are discussed. One, apparently of Lower Cenomanian age, is referred to the rather doubtful genus Keckia (Fig. 1). The other, from the Gault, is referred to Granularia (Fig. 2). Both these genera are held to be of Annelid origin.