CERATIOCARIS ? LONGICAUDA. 61 



calcareous at tlie edge. Here we have probably two valves, i^ressed together and 

 crumpled ; a film of smooth test is visible ; the segments are continued inwardly. 

 An obscure, filmy, lineated, sharply-elliptical body, lying obhquely just above the 

 anterior point of the valve, may be a relic of the rostrum. There are three outer 

 segments and a strongly-ridged, sharp telson, 



PI. VII, fig. 4. The specimen, Ludlow Museum K, is in a greenish-grey, non- 

 calcareous, finely micaceous mudstone. Lower Ludlow. From the old roadside 

 quarry south-east of Trippleton, Collected by Mr. A. Marston. 



Carapace with almost perfect outline of the embedded left valve, but with only 

 a fragment of the outside of the right valve (posterior third) ; purplish in tint ; 

 marked with parallel striee wide apart, and with transverse cracks. The marginal 

 rim is strong, as shown by the impression. 



There are three abdominal segments exposed, and indications of others. The 

 caudal appendages are rather obscure. 



PI. VII, fig. 5. Oxford Museum L. In Lower-Ludlow yeUo wish-grey, finely 

 micaceous mudstone, not calcareous. 



Carapace represented by a hollow impression of the right, and a postero-dorsal 

 fragment of the left valve. The outline is well preserved, subovate, straight on 

 the postero-dorsal edge, which terminates with an angle above the medial line of 

 the valve, over a slightly ogee curve on the truncate end. The anterior 

 curves meet in an elegant point almost on the medial line. A small mass of 

 obscure organic matter occupies the antero-dorsal region. Indistinct longitudinal 

 striae are traceable on the remnant of the left valve. The ventral rim of the right 

 valve is indicated by a strong impression on the matrix, with a few delicate striae 

 near by. Three abdominal segments, with a telson and one stylet, ai'e attached ; 

 all apparently smooth, but under the microscope there are traces of a fine lineation 

 on the segments. The appendages, not exposed to their ends, are rugose with 

 pits, due probably to decomposition. 



28. Ceeatiocaeis (?) longicauda (D. Sharpe), 1853. PI. XI, figs. 16 a, 16 h. 



1853. DiTHXBOCAEis ? LONGICAUDA, Z). /Sharpe. Quart, Journ. Geol. Soc, vol. 



ix, p. 158, pi. 7, fig. 3. 



1885. Ceeatiocaeis ? longicauda, T. E. J. & H. W. Third lleport Pal. Phyll., 



p. 354. 



1886. _ _ — Fourth Report, p. 233 ; 



Geol. Mag., 1886, p. 460. 



The ultimate segment and trifid appendage of a small Ceratiocarid of uncertain 



