PLATE XI. 



(All the figures are of the natural size except figs. 4 b, 13 b, and 16 b.) 



Fig. 1. — Geratiocaris stygia (?), Salter. Two abdominal segments, with a style 

 and a stylet, well preserved. Cambridge Mus. (Page 41.) 



Fig. 2. — G. longa, T. R. J. & H. W. Caudal extremity (wanting one stylet), 

 flattened. Ludlow Mus. (Page 43.) 



Fig. 3. — G. stygia, Salter. Two abdominal segments, style, and stylet, squeezed 

 sideways. Mus. Pract. Geol. (Page 41.) 



Figs. 4 a, 4 b. — G. papilio, Salter. 4 a, four segments, style, and stylet, squeezed 

 sideways ; 46, portion of leaf-like ornament (X 3 diam.). Oxford Mus. (Page 38.) 



Fig. 5. — G. longa, T. R. J. & H. W. One segment, style, and stylet, like 

 fig. 2. Mus. Pract. Geol. (Page 43.) 



Fig. 6. — G. papilio, Salter. Four segments and trifid appendage, pressed flat. 

 British. Mus. (Page 38.) 



Fig. 7. — G. stygia, Salter. Two segments with telson and stylet, pressed 

 sideways. Oxford Mus. (Page 41.) 



Fig. 8. — G. robusta, Salter. Telson and stylet, squeezed sideways. The original 

 of fig. 7 e, ' Brit. Pal. Foss.,' 1851. Cambridge Mus. (Page 45.) 



Fig. 9.— The same. A stylet. The original of fig. 7 d in the < Brit. Pal. Foss.,' 

 1851. Cambridge Mus. (Page 45.) 



Fig. 10. — G. minuta (?), T. R. J. & H. W. A trifid appendage, not quite 

 perfect at the top. Mus. Pract. Geol. (Page 47.) 



Fig. 11. — G. patula, T. R. J. & H. W. A flattened trifid of broad caudal 

 spines. Oxford Mus. (Page 46.) 



Fig. 12. — G. robusta (?), Salter. Cast of a trifid appendage (small). British 

 Mus. (Page 45.) 



Figs. 13 a, 13 6. G. robusta, Salter. 13 a, style and stylet, pressed sideways. 

 13 b, portion of the pitted row, magnified 3 diam. British Mus. (Page 45.) 



Fig. 14. — The same. Style and displaced stylet. British Mus. (Page 45.) 



Fig. 15. — The same. A perfect trifid, flattened. British Mus. (Page 46.) 



Figs. 16 a, 16 b. Geratiocaris (?) longicauda, D. Sharpe. Portugese specimen. 

 16 a, ultimate segment and trifid appendage ; 16 b, part of the style and of a stylet 

 enlarged X 3 diam (Page 61.) 



