464 Pro/. T. Biqoert Jones and Br. S. Woodward — 



Specimen Lud. Mus. J. (from Trippleton, near Leintwardine) has 

 a smaller but nearly similar carapace (22 x 12 mm.) ; nearly 

 straight on the back, deeply curved below, and with almost equal 

 dorsal angles in front and behind, but sharp instead of being blunt. 



13. Ceratiocakis robusta, Salter. 



185 1. Pterygottis lepiodadylus, M'Coy (in part). Brit. Palseoz. Foss. fasc. i. 



p. 175, pi. I E. figs. 7^, 7^. 



i860. Ceratiocaris robttstus, Salter. Ann. Mag. N. H. ser. 3, vol. v. p. 158. 



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



1873. ,, ,, Salter. Cat. Camb. Sil. Foss. p. 164.. 



1877. ,, ,, H. Woodward. Cat. Brit. Foss. Crust, p. 71. 



1878. „ „ Huxley and Etheridge. Cat. Camb. Sil. F. M. P. G. 



p. 142. 



This species was fomided on the caudal appendages of a form 

 the carapace of which has not j^et been collated. The original speci- 

 mens figured by M'Coy and referred by Salter to a new species are 

 in the Cambridge University Museum (a/925, fig. 7c; a/926, fig. Id). 

 The telson, 32 mm. long (longer than the figure), is straight, broadly 

 ensiform, 6 mm. broad at its base. The stylets, 20 mm. long, are 

 also relatively broad and ensiform or sharp-blade-like. They all 

 seem to have once been faintly fluted and ridged or costulated. They 

 were from Leintwardine (Lower Ludlow). 



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

 Upper Ludlow beds, "above Ashley Moor," are in the Owens Col- 

 lege 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. 



B. M. 39404, from Leintwardine, belongs to the same species, 

 though the style is rather longer (35 mm.). 



Also M. P. G. --tf (Catal. 1878, p. 142), from Leintwardine, seems 

 to belong to this form. It shows two segments and appendages. 

 Style, 40 mm. ; one stylet present, broad and ensiform, 25 mm. long. 



Specimens A. and H. in the Oxford Museum are good examples of 

 C. robusta, of rather large size, the style of one being 45 mm. long, 

 and of the other 35 mm. Some segments also are in place, and 

 show a neat imbricate ornament of angular raised lines, passing 

 downwards on the sides into delicate oblique wrinkles. S. and T. 

 in the same Museum are short trifids with broad style and stylets 

 agreeing more closely with M'Coy's original specimens. They are 

 faintly fluted, and there are on one style two rows of the bases of 

 little prickles. All from the Ludlow formation. 



Var. long a. 

 Specimen Ludlow Museum M. is a broad and much longer telson 

 (at least 75 mm. long), with linear ornament, from the Lower Lud- 

 low at Bow Bridge, Ludlow. A small part of a slightly curved 

 ensiform stylet shows from beneath it. This may be either a variety 

 of C. robusta, or possibly a distinct species, near to C. papilio. 



14. Ceratiocaris, sp. nov. ? 

 In Owens College Museum, Manchester, is a very delicate little 



