394 Frof. T. Rupert Jones and Dr. H. Woodioard — 



In anotber, but smaller, individual (Brit. Mus. 41895) the cara- 

 pace, 40 X 20? mm. ; segments, 40 mm., but shortened ; and style, 

 about 20 mm, (stylets, 15 mm. each), make about 100 mm., or four 

 inches, of total length. 



In ten good specimens from Lesmahago we have seen two of cara- 

 pace only ; and in all the others the body-portion is shifted, and in 

 six of them it is quite reversed — that is, lying at the anterior instead 

 of the posterior end, as described by Mr. Salter (Siluria, 1867, p. 

 236, etc.). 



The specimen Cambridge Mus. 6/135 has the rostrum lying at an 

 angle across the anterior extremity. 



Of C. papilio, good specimens from Lesmahago : — 



Cambridge Mus., &/135. M. P. G. x iV, x -^V. 



Brit. Mus. 41894, 41895, 41896, 41897, 45161, 47989, 58669. 



We have seen also some fossil carapaces from Benson Knot, Ken- 

 dal (Upper Ludlow), which agree perfectly in form and proportions 

 with C. papilio from Lesmahago, also in ornament, except that the 

 postero-dorsal convergence of the striae is not present. These are 

 Brit. Mus. some of those marked 44342 ; M. P. G. x l (Catal. 1878, 

 p. 141) ; and Cambridge Mus. &/35. They range from 65 mm. long 

 and 32 mm. high to 75 x 40 mm. Also a large imperfect specimen 

 and some fragments in brown shale from Linburn near Muirkirk 

 (Brit. Mus., all marked 58878.) The specimen 6/35 is included in 

 a inornata, M'Coy, by Mr. Salter, Catal. C. S. Foss. 1873, p. 177. 



Moreover, the specimen N in the Ludlow Museum has the pro- 

 portions and appearance of C. papilio, as far as it is preserved 

 (wanting the antero-dorsal angle), from Church Hill, Leintwardine.^ 



4. Ceratiocarts stygia, Salter. (PI. X. Fig. 2.) 



1859. Ceratiocaris^ Salter. In Murchison's Siluria, 2nd (3rd) ed. p. 262, wood- 

 cut fig. 2. 



i860. Ceratiocaris stygius, Salter. Ann. Mag. Nat. Hist. ser. 3, vol. v. p. 154, 

 woodcut figs. 2, 3 (fig. I is C. papilio). 



1865. Cej-atiocaris papilio, Salter and Woodward. Cat. and Chart Foss. Crust, p. 



17, fig. 5- 

 1867. Ceratiocarts stygius, Salter. In Siluria, 3rd (4th) ed. p. 236, woodcut fig. 2, 



and p. 517. 

 1873. Ceratiocaris stygius, Salter. Cat. Camb. Sil. Foss. p. 178. 

 1873. ,, ,, R. Etheridge, jun. Mem. Geol. Surv. Scotl. Expl. 



Map 23, pp. 55, 56. 

 1876. Ceratiocaris papilio. Roem. Leth, geogn. Th. i. Leth. palseoz. pi. 19, fig. 4. 



1876. Ceratiocaris stygius, Armstrong and others. Cat. W. Scot. Fossils, p. 24. 



1877. ,, „ H. Woodward. Catal. Brit. Foss. Crust, p. 73. 



1878. ,, ,, Huxley and Etheridge. Cat. Camb. Sil. Fossils, p. 142. 



Carapace -valves trapezoidal ; back straight, but curving down for 

 a short distance to the mucronate dorsal angle of the anterior edge, 

 which then slopes with a slight convexity at a sharp angle, down- 



' The very rich localities for these Silurian PhyUopods in the neighbourhood of 

 Ludlow are enumerated and described in the Eev. J. D. La Touche's Handbook of 

 the Geology of Shropshire, 1884, pp. 26, 27, especially Ludford Lane, Bow Bridge, 

 Leintwardine, Church Hill, and Trippleton Farm. See also the Eev. W. S. 

 Syraonds' Record of the Rocks, 1872, p. 194, etc., for notices of Ludlow and its 

 environs from a geologist's point of view. 



