BRITISH FOSSILS. 97 



being rather below the upper third 5 the base is rather suddenly 

 contracted, and tongue -shaped. 



Thoracic (?) Appendage, Plate XIII. fig. 16. This has been 

 already alluded to (p. 92), as probably belonging to the species. It 

 is more perfect than any other specimen, though only the impression 

 of one side. The large ovate terminal plate a b, shows well the gra- 

 dation between the ordinary plicae and the long lateral plaits, the 

 middle line is bare of any ornament. At the apex are seen two or 

 three of those impressed lines, which are so much more conspicuous 

 on the opposite surface, and which seem to divide the plate into 

 laciniae, a. The plate is indented at its basal end, corresponding to 

 the central depression (ridge in the cast) of the preceding joint. This 

 joint is very irregular in shape, the lobes on one side, d, being single, 

 on the opposed side c double. Both are marked with minute plicae 

 near the edges. 



Locality. The above-mentioned fragments have all successively 

 come to light during the active researches of the Ludlow geologists 

 in the quarries of LOWER LUDLOW ROCK at Leintwardine, parti- 

 cularly in one at Church Hill. There are many new Crustacea to be 

 described from the same quarry, of one of which the head portion 

 has been accidentally introduced into this plate. Plate XIII. 

 fig. 17- See also p. 25, suprct. 



