CERATIOCARIS VALIDA. 21 



The caudal appendages only are known ; they are very stout, curved at first 

 downwards and then upwards. The style (about 125 mm. long) is strongly ridged 

 and fluted, and it is pitted along two lines, one on each side. The stylets are 

 ridged and 90 (?) mm. long. The heads of style and stylets are wrinkled length- 

 wise. A fragment of the ultimate segment, attached, shows that it was orna- 

 mented with straight wrinkles. The specimens from the Wenlock-beds of Dudley 

 and Kirkby Lonsdale, described and figured in the ' Geol. Mag.,' 1866, p. 204, pi. 

 10, figs. 8 and 9, as belonging to G. Mnrchisoni, are too thick and strong for that 

 species, and the Dudley example (fig. 8) has different proportions. We propose to 

 distinguish them as C. valida. 



PL VI, figs. 10, 11. Copied from the ' Geological Magazine,' vol. iii, 1866, 

 pi. 10, figs. 8, 9. Wenlock Shale, Dudley, collected by Mr. HoUier. 



Fig. 10. ' Geol. Mag.,' vol. iii, p. 204, pi. 10, fig. 8, " C. Mnrchisoni," in Dr. H. 

 Woodward's paper " On the Occurrence of Geratiocaris in the Wenlock Formation 

 (Upper Silurian) of England." Portion of a style (telson), attached to a si.. '1 

 piece of an ultimate segment, and two stylets, one with a sharp perfect end, the 

 other somewhat shortened. All are grooved and ridged, and the telson bears a 

 row of strong puncta along one side of its outer ridge. The describer writes : 

 " The specimen from Dudley has been partially worked out on the upper edge of 

 the slab of shale on which it rests, so as to expose both sides of the central spine 

 (telson) ; and, although much flattened, it exhibits another row of punctations 

 corresponding to that seen in the plate, and two intermediate dorsal furrows." 



Fig. 11. Op. cit, fig. 9. (Mus. Pract. Geol. ||-) ' Catal. Camb. and Sil. Fos.,' 1878, 

 p. 84. From Casterton Low Fell, Kirkby Lonsdale, Westmoreland. The section 

 of the strata of this hill, with the Barbon Low Fell adjacent, is figured and de- 

 scribed by Prof. T. McKenny Hughes in the ' Geol. Mag.,' vol. iii, pp. 206 — 208. 

 Cardiola interrupta is a prominent fossil in these beds, which are equivalent to the 

 Denbighshire Grits of the Wenlock series. Portions of telson and two stylets, all 

 ridged ; the former pitted along the side of its outer ridge. 



Fig. 12. Op. cit., fig. 10. (British Museum.) The head of a telson fi'om the 

 Silurian strata of Bohemia, showing the arrangement of two parallel rows of pits 

 on longitudinal ridges, one on each side of the back with a median dorsal ridge 

 between them. This may probably have been the arrangement in the English 

 specimens, figs. 10 and 11 (and others), before they were modified by pressure. 



Mr. G. J. Williams, F.G.S., of Ffestiniog, has a good, though imperfect, specimen 

 of the caudal spines, from the Wenlock Shale of Harp Hollow, near Welshpool. 



C. VALIDA. — Carapace not known. Ultimate segment. — Striated longitudinally. 

 Caudal spines. — Thick, flexuous, ridged and fluted. Style. — Punctate on each side 

 of its dorsal ridge. 



