CERATIOCARIS MURCHISONI. 19 



PI. IV, fig. 3. A set of caudal appendages, imperfect at the ends. One semi- 

 circular acetabulum on the telson head for articulation with the angle of the ulti- 

 mate segment, and the other (below) for a stylet (broken across its neck), are well 

 shown. Pitting present on the style ; none on stylets. Style and stylets ridged 

 and fluted. Oxford Museum 0. Lower Ludlow. Olive-grey sandstone. 



PI. V, fig. 3. A style (telson) and a stylet, both having longitudinal smooth 

 ridges, partly preserved. The telson seems at first sight to show five ridges, but 

 there are really two main lateral i-idgcs, one delicately keeled for part of its length, 

 and the other (nearer the dorsum) is deeply fluted, and in the furrow is a series of 

 small sub-oval pits, each with a central nipple, the bases of former prickles. In 

 greenish-grey mudstone, not quite uniform in texture, and mottled with brownish 

 patches ; calcareous in parts. Ludlow Museum 0. Lower Ludlow. Church Hill, 

 Leintwardine. Collected by Mr. H. Pardoe. This specimen C (fig. 3) was cemented 

 to B (PI. v., fig. 1), and labelled " Ceratiocaris Pardoensls" in the Ludlow 

 Museum, but they do not correspond, being exposed with different aspects, and not 

 agreeing in size and proportions. 



Plate VI, figs. 1 and 2. Copied from ' Siluria,' 8rd edition (published as 

 the 4th, including the ' Silurian System '), 1867, pi. 19, figs. 1 and 2, which 

 had been transferred as lithographs from the engravings in the ' Silurian System,' 

 1839, pi. 4, figs. 10 and 64, to ' Siluria,' 1st edition (published as the 2ud), 1854, 

 pi. 34, fig. 1, and pi. 35, fig. 13. 



Fig. 1. ' Siluria,' 1854, Leptocheles, pi. 19, fig. 1 ; 1867, pi. 19, fig. 1. 

 ' Silurian System,' 1839, Onchus, pi. 4, fig. 10, said to be from the Uppermost 

 Ludlow Beds (" the Downton series ") at the Tin Mill, Ludlow. Fragments of a 

 style (telson) and two stylets, all ridged and furrowed. The broken piece lying 

 obliquely at the top is evidently a part of the style, and not of a stylet, as its end 

 lies upon the former. Some small spots at the lower end of the style possibly 

 indicate the bases of prickles. 



Fig. 2. 'Sil. Syst.,' 1839, Ichthyodorulite, pi. 4, fig. 64; 'Siluria,' 1854, 

 Leptocheles, pi. 19, fig. 2; ' Siluria,' 1867, pi. 19, fig. 2. Fragment (proximal end) 

 probably of a ridged style, its shape modified by embedment. A line of dots seems 

 to be referable to the bases of prickles. 



C. Mdechisoni. — Carapace. — Not known. 



Segments. — Straight wrinkles passing backwards into lattice-pattern at the edge. 

 Appendages. — Long and strong, slightly curved, convexity dorsal. 

 Telson. — Ridged and fluted, pitted along two rows (one on each side) ; slightly 

 curved downwards. 



Telson-head. — Irregular wavy stri^ with partial lattice-work ornamentation. 

 Stylets. — Ridged and fluted. 



