44 BRITISH PALEOZOIC PHYLLOCAR1DA. 



13. Ceratiocaeis robusta, Salter, 1860. PI. X, fig. 10; PL XI, figs 8, 9, 



12—15. 



1851. Pterygotus leptodactylus, M'Coy (in part). Brit. Palseoz. Foss., fasc. i, 



p. 175, pi. IE, figs. 7 c, 7 d. 



1860. Ceratiocaris robustus, Salter. Ann. Mag. Nat. Hist., ser. 3, vol. v, p. 158. 



1865. — — H.SfE. Catal. Foss. M. P. G., p. 79. 



1867. — Salter. In Siluria, 3rd (4th) edit., p. 516. 



1873. — — — Catal. Camb. and Sil. Foss., p. 164. 



1877. — — H. Woodward. Catal. Brit. Foss. Crust., p. 71. 



1878. — — (part) H. JV. 8f JE. Catal. Camb. and Sil. Foss. 



M. P. G., pp. 84 and 142. 



1885. — robusta, T. B. J. & H. W. Third Eeport Pal. Phyll., p. 349 ; 



G-eol. Mag., 1885, p. 464. 



1886. — Fourth Eeport, p. 231 ; Geol. 



Mag., 1886, p. 457. 



This species was founded on the caudal appendages of a species the carapace 

 of which has not yet been collated. Hence the species is unsatisfactory to deal 

 with. The original specimens figured by M'Coy, and referred by Salter to a new 

 species, are in the Cambridge University Museum (a/925, M'Coy's fig. 7c; a/926, 

 fig. 7 d). The telson, 32 mm. long (longer than the original figure), is straight, 

 broadly ensiform, 6 mm. wide at its base. The stylets, 20 mm. long, are also 

 relatively broad and ensiform or like a sharp blade. They all seem to have once 

 been faintly fluted and ridged, or costulated. They were obtained from Leint- 

 wardine, where they occur in the Lower Ludlow Beds. 



Two similar specimens, collected by the late Mr. Lightbody in Upper- Ludlow 

 Beds, " above Ashley Moor," are in the Owens College Museum, Manchester. One 

 of the sets, however, has the stylets nearly as long as the style ; whether this was 

 due to variation of growth or to accident, we cannot now decide. The locality is 

 near Richard's Castle, not far from Ludlow. 



Oxford Mus. S is a short trifid appendage (not figured), with a style 23 mm. and 

 stylets 13 mm. long; the latter smooth and with a slightly raised rim at the 

 margin ; the former faintly fluted and pitted. 



PI. VI, fig. 3. Copied from ' Siluria,' and formerly referred to C. robusta, 

 seems to be too large and too much curved for a stylet of the usual form of that 

 species; but it may have belonged to C. longa (see page 43). 



PI. X, fig. 10. Mus. Pract. Geol. ff (' Catal.,' 1878, p. 118). In olive-green 

 shale ; slightly micaceous, not calcareous. Lower Ludlow ; Leintwardine. 



