PLATE I. 



Pig. 



1. 



2. 



3. 



4. 



5. 



6. 



7. 



8. 



9. 

 10. 

 11. 



12. 

 13. 

 14. 

 15. 

 16. 

 17. 

 18. 

 19. 

 20. 

 21. 

 22. 

 23. 

 24. 

 25. 

 26. 

 27. 

 28. 

 29. 

 30. 

 31. 

 32. 

 33. 

 34. 

 35. 

 36. 

 37. 

 38. 

 39. 

 40. 

 41. 

 42. 

 43. 

 44. 

 45. 

 46. 

 47. 

 48. 

 49. 

 50. 

 51. 

 52. 



53. 

 54. 

 55. 



56. 



57. 



58. 



59. 



60. 



61. 



62. 



63. 



64. 



65. 



66. 



67. 



68. 



69. 



70. 



71. 



72. 



73. 



74. 



75. 



76. 



77. 



Cytheridea perforata (Komer). (Page 29.) 



Cytheropteron concentricum (Reuss). 



Lelt (larger) valve. 

 Right (smaller) valve. 

 Right valve, inside. 

 Left valve, inside. 

 (Page 31.) Worn, old carapace, showing left valve. 



— — Left valve, rather young, prickly. 



— — Left valve, older, wrinkled. (See also PI. IV, fig. 19.) I , g 



— — Left valve, dorsal edge. >■ x io 



— — Left valve, inside. 



— — Anterior view of a carapace. 

 mnbonatum (Will.), var. acantlwptera (Marsson). (Page 41.) (See also PI. IV, figs. 22 — 



24.) Left valve. 



— — — — Dorsal view. 



— — — — Posterior view. 

 concentricum (Reuss), var. virginea, Jones. (Page 32.) Carapace, oblique. 



— ■ — — — Left valve. 



— — — — Ventral view. 



— End view. 



Right valve. 

 Dorsal view. 

 Anterior view. 

 Carapace, ventral view. 

 Carapace, dorsal view. 



— — — Carapace (thin), ventral outline. 



— — — Carapace (large), posterior view. 



— — — Carapace, ventral view, oblique. 



— — — Carapace, dorsal view. 

 Bythocypris simulata (Jones). (Page 11.) Carapace (damaged at the posterior end), showing the right valve. 



— — — Dorsal aspect. 



— — — Anterior aspect. 

 Cythere Bairdiana, Jones. (Page 15.) Right valve, inside. 



— — — Dorsal aspect. 



— — — End outline. 

 Cytheropteron Sherborni, sp. nov. (Page 42.) Left valve. 



— — — Right valve, ventral edge and inside. 



Cythere gaultina, Jones. (Page 18.) Right valve. 



— — — Dorsal aspect. 

 Cythereis Iceniea, sp. nov. (Page 26.) Right valve. 



— — — Right valve. 



— — — Dorsal aspect. 



— Lonsdaleana, Jones. (Page 27.) 



X ISdiam. 



— sphenoides (Reuss). (Page 33.) 



— umbonatum (Will.). (Page 40.) 



Cythere Sarrisiana, Jones, var. setosa, nov. (Page 17.) 



— var. reticosa, nov. (Page 18.) 



— (Page 16.) Ordinary form 



— Var. a. ~ 



— Var. /3. 



— Var. /3. 



— Var. a. 

 Var. 13. 



Cythereis auriculata (Cornuel). (Page 19.) 



triplicata (Romer). (Page 19.) 



Right valve. 



Edge outline. 



End outline. 



Right valve. 



Left valve. 



Left valve. 



Right valve. 



Left valve. 

 Lett valve. 

 Left valve. 



Carapace, dorsal aspect. 

 Carapace, ventral aspect. 

 Carapace, anterior aspect. 



xl8 „ 



xl8 „ 



x20 „ 



x20 „ 



xl8 „ 



x20 „ 



xl8 „ 



xl8 „ 



xl8 „ 



x20 „ 



xl8 „ 



xl8 „ 



■ X 20 „ 



> x25 



Right valve. 



Right valve. 



Right valve (deformed). 

 Left valve. 

 Right valve. 



— — Right valve, inside. 



— — Carapace, dorsal aspect. 



— — Left valve, inside. 



— — Carapace, anterior aspect. 



Iceniea, sp. nov., var. quadrata, nov. (Page 27.) (See also PI. IV, figs. 15- 

 ornatissima (Reuss), var. stricta, nov. (Page 25.) Right valve. 

 Lonsdaleana, Jones. (Page 27.) Left valve. 



— — Right valve. 



— — Dorsal edge of right valve. 

 ornatissima (Reuss), var. reticulata, nov. (Page 24.) Left valve. 



— Left valve. 



Left valve. 

 Right valve. 

 Carapace, dorsal aspect. 

 Carapace, anterior aspect. 

 Left valve, not full grown. 

 Right valve, young. 

 Carapace, young ; dorsal aspect. 

 (Page 23.) Left valve, 

 nov. (Page 24.) Left valve. 



. xl8 



■ X 25 „ 



I 



-17.) Left valve. 



quadrilatera (Roraer). (Page 20.) 



ornatissima (Reuss), var. nuda, nov. 

 — — var. reticulata. 



xl8 „ 



x20 „ 



x20 „ 



xl8 „ 



x20 „ 



xl8 „ 



x25 „ 



