H. Woodward — On Ceratiocans. 205 



From the foregoing list it will be seen that all the ten species 

 enumerated belong either to the Upper or Lower Ludlow Eock ; but 

 I find that Mr. Salter, so far back as November 1855, was aware of 

 an older species, for he says (Quart. Journ. G-eol. Society, Vol. xii., 

 pp. 33 and 34) " the occurrence of body-rings in the Dudley Lime- 

 stone has been for some time known ; and in the Ludlow Museum I 

 lately saw such body-segments connected -wdth the long triple tail- 

 spines now known under the name of Leptoclieles." And, again, " the 

 carapace and some of the body -joints were found near together by 

 Mr. John Gray of that jolace (Dudley) ." In his paper in the " Annals " 

 (in 1860) ah-eady quoted, Mr. Salter observes, — " I believe there are 

 other forms of the genus even in Britain, besides these nine or ten 

 species which have all turned up in the course of a year or two. 

 Abroad still larger specimens have been found in Upper Silurian 

 rocks. M. Barrande has figured the tail-spines of three species, of 

 which Leptoclieles Boliemicus has the greatest resemblance to our 

 Ceratiocaris Miirchisoni ; and a large species, C. Dewii, has been 

 figured as a fish-defence, by Hall, from the Niagara Limestone of 

 New York. Oiu' own Dudley Limestone contains one species ; but 

 the metropolis of this curious Silurian ' shrimp ' is ia the Lower 

 Ludlow Eock, where it keeps company with Pterygoti and other 

 large Crustacea.^ It appears not to have been a long-lived genus, for, 

 as yet, none have been detected below the Wenlock Limestone, or 

 above the Upper Ludlow rock." 



It thus will be seen that Mr. Salter has anticipated the announce- 

 ment of the occurrence of Ceratiocaris in the Wenlock Limestone, 

 although' he does not refer it to any one species. 



There is little doubt that this is one of the largest British forms 

 of Ceratiocaris, but in the absence of the carapace and body segments, 

 I do not feel justified in adding another species to the burden of 

 pal^ontological nomenclature. The characters seen in this telson 

 ap]3ear to be common alike to C. Murcliisoni, C. rohustus, and C. 

 Bohemicus. If it must be christened, I would recommend the adop- 

 tion for it of the name of Sir E. I. Murchison (King of SUuria), as 

 the oldest and best known.^ Any apparent difference in the specimens 

 figured is due to the difference of condition ia which they are pre- 

 served — Fig. 9 being only a cast, whilst Fig. 8 stOl retains its shelly 

 structure, 



I have not figured the fragment from the Coniston Grrit (Lower 

 "Wenlock), Helm Knot, Dent, Yorkshire, as it was too small. The 

 specimen from Kirkby Lonsdale (Fig. 9) gives us a new locality, 

 and a fresh horizon, which Mr. Hughes kindly describes. Frag- 

 raentaiy as these remains may appear, yet they nevertheless point to 

 a further extension in time of the genus Ceratiocaris, and may be the 

 means of exciting the search for more perfect specimens. 



' Not only do we now find spines of Ceratiocaris in tlie "Wenlock Limestone, but 

 numerous portions of Pterygoti have been met witb by Messrs. John Gray, C. Ketley, 

 L. P. Capewell, E. Hollier, and other gentlemen, at Dudley, and its vicinity. — H. W. 



^ In the second edition of " Siluria," these striated tail-spines are represented in 

 Plate 19, Fig. 1 and 2, from the Uppermost Ludlow Eock, Ludlow, and are there 

 correctly named Ceratiocaris Murohisoni, by Mr. Salter. 



