CERATIOCARIS GIGAS. 25 



much broader than that in M. P. G. ff , PL III, figs. 2, 3. For instance, Oxford Mus. 

 F ; M. P. G. x | ; Ludlow Mus. T. One of these (x ^) has been labelled G. gig as by 

 Mr. Salter, and therefore we adopt that name. 



Only the ultimate segment and the three caudal spines are known. The former 

 is large, being broad and strong, and is marked with longitudinal wrinkles ; the 

 latter are long, straight, and ridged. The style is strongly fluted and pitted, and 

 its head bears the leaf- or lattice-pattern. 



The characteristic fragment of this species, in the Museum Pract. Geology, 

 marked x \> aud labelled G. gigas by Mr. Salter, was entered in the ' Catalogue 

 of Fossils,' 1865, under that name. 



PI. Ill, fig. 1. An ultimate segment, and upper portion of caudal appendages 

 crushed. This segment has thin longitudinal wrinklets ; and its terminal rim is 

 regular for a part of its length. The head of the telson is bulbous, and below it 

 the tops of the caudal spines are crushed. The telson is ridged. Mus. Pract. 

 Geol. Marked " x |. Lower Ludlow; Danefield, Kington. Ceratiocaris gigas? 

 Salter. Presented by J. W. Salter, Esq." See ' Catal.,' 1878, p. 141. Darkish 

 olive-grey micaceous mudstone. 



PI. IV, fig. 2. Ultimate segment and caudal appendages. The head of a stylet 

 is close to a semicircular acetabulum under the shoulder of the telson-head. Stylet, 

 55 mm. long ; style probably twice as long. 



Articulation between telson and lower angle of ultimate segment almost perfect. 

 Under or inner flange at top of the telson well preserved (brown-black). Inoscu- 

 lating angular wrinkles on telson-head making minute leaf-marks. 



Strong, raised, interrupted, inosculating, longitudinal wrinkles on the ultimate 

 segment; also semicircular facet for the preceding segment. Oxford F. In 

 greenish-grey mudstone, weathering brownish ; calcareous at the edge, along very 

 thin seams. Lower Ludlow. 



PI. V, fig. 5. An ultimate segment, like that of PI. IV, fig. 2 ; but, though 

 crushed, more perfect at its upper dorsal angle. The articulation for the preceding 

 segment is well preserved. The longitudinal sculpture of anastomosing wrinklets 

 is very distinct on this purplish specimen. Ludlow Museum T. In light greenish- 

 grey micaceous mudstone, calcareous. Marked " Lower Ludlow ; Church Hill. 

 G. gigas. H. Pardoe." 



Specimens corresponding in character with G. gigas are : 1. Ludlow Museum 

 R, a broken ultimate and imperfect appendages, from Church Hill, Marston Coll. 

 2. Parts of a straight style and stylet ; as a ferruginous cast. From the Upper 

 Coldwell Beds (— Wenlock), South of Coldwell Quarry, Windermere. Cambridge 

 Museum ; Marr Collection. 



Either G. gigas or G. Murchisoni : 1. Fragment of a straight, strong telson. 

 Ludlow beds ; Bury Ditches, Salop. British Museum. 2. Fragment of a caudal 



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