PLATE XVII. 

 Fio. 



1. Discinocaris gigaf, H. Woodward. Left-hand lower corner of a test. British 



Museum. (Page 122.) 



2. — — — Crushed portion of a test. Cambridge 



Museum. (Page 123.) 



3. — — • — Sketch of a large specimen by the late Mr. 



James Dairon. (The dotted outline has 

 been added to show the more probable 

 form of the shield. The lateral margins 

 in Mr. Dairon's figure are evidently 

 artificial, and not the true margins ; nor 

 does it show the real antero-lateral 

 angles. Figs. 1 and 2 indicate the true 

 shape of the postero-lateral angles, and 

 the way in which the lines of growth 

 die out at the margins.) (Page 123.) 



4. — (?). Fragment. British Museum. (Page 123.) 



5. — (?). Some imperfect body-rings, flattened. British Museum. 



• (Page 123.) 



6. Aptychoims Salteri, H. Woodwai'd. Right-hand valve. British Museum. 



(Page 109.) 



7. PeUocaris Garruthersii, sp. uov. Carapace. Copied from the ' Quart. Journ. 



Geol. Soc.,' vol. xxii, pi. 25, fig. 6. (Page 

 116.) 



8. Tail-piece. British Museum. (Page 124.) 



9. 10, 11, 12. Tail-pieces. Cambridge Museum. (Page 124.) 



