16 BRITISH PALEOZOIC PHYLLOCARIDA. 



bearing indications of two rows of the bases of prickles on its upper portion, and 

 thus corresponding with fig. 4 ; it is imperfect at the end. The others are pro- 

 bably perfect in length. 



Fig. 8. A similar, but smaller, set of caudal appendages ; all ridged ; only the 

 style retaining its full length. 



Fig. 9. Style and stylets pressed together. The end of the former is still in 

 the matrix. Some indistinct traces of spine-bases are seen on its lower portion, 

 but not represented in the drawing. 



PI. X, fig. 8 (British Museum 44342). Benson Knot, 1 Kendal. Dark grey 

 sandstone, somewhat micaceous, and slightly calcareous. 



C. leptodacttlus. — Carapace. — Not known. 



Ultimate Segment. — With longitudinal anastomosing wrinklets. 



Caudal Appendages. — Slender, ridged and fluted. 



Head of Telson. — With lattice ornament and anastomosing longitudinal wrinklets. 



Style (telson). — Fluted, and pitted in two rows on the side (as exposed). 



Stylets. — Delicately fluted. 



Length of Fig. 4. Fig. 5. Fig. 7. Fig. 8. Fig. 9. 



Style 65 mm. ") 65 mm. 50 mm.") 40 mm. 50 mm. ") 



} 



(imperfect). -) (broken). > (imperfect). ' 



Stylet — — 55 mm. — 28 mm. 



A specimen in the Museum of Practical Geology, marked d f-f (' Catal. Cambr. 

 and Sil. Fos., M. P. G.,' 1878, p. 118), from Dudley, a thin curved telson (?), 

 delicately striate, is probably C. leptodactylus. 



In Barrande's ' Syst. Sil. Boheme,' vol. i, Supp., pi. 19, figs. 14 — 16 of 

 C. incequalis are comparable with C. leptodactylus. 



2. Ceratiocafjs Murchisoni (Agassiz), 1839. PI. Ill, figs. 4a, 4b, 7 ; PI. IV, figs. 

 1 and 3 ; PI. V, fig. 3 ; PI. VI, figs. 1 and 2. 



1839. Onchus Mubchisoni, Agassiz. In Silur. Syst., p. 607, pi. 4, fig. 10 (not 



figs. 9 and 11) ; and Onchus, fig. 63 ?, 

 and Icbthyodorulite, fig. 64. 

 1851. Leptocheles (Mubchisoni), WCoy. Synops.Brit. Pal.Foss.,Fasc. 1, p. 176. 

 1853. — Mubchisoni, — Quart. Journ. Geol. Soc, vol. ix, 



p. 13 (omitting allusion to figs. 9 

 and 11, Sil. Syst). 

 1853. Dithtbocaeis Oeinitz. Verstein. Grauwackenformation in 



Sachsen, Heft ii, p. 24, pi. 19, fig. 13. 



1 " The micaceous flags of Benson Knot belong to what are locally called ' Kirkby-Moor Flags ' 

 — i. e. Upper Ludlow."— Prof. T. M'K. Hughes, ' Geol. Mag.,' vol. iii, \). 208. 



