38 North American Palaeozoic Crustacea. 



the variety rugulosa. Magnified 70 diam. 7 c, The external aspect 

 of the muscle-spot in C. Aynes. Magnified 70 diam. 



Fig. 8. Cypridina Phillipsiana, .Jones. Carboniferous, Ireland. 8 a, Right 

 valve. 8 b, Ventral edge. Magnified 3 diam. 



Fig. 9. Cypridella Koninckiana, Jones. Carboniferous, Ireland. 9 a, Right 

 valve. 9 b, Ventral edge. Magnified 8 diam. 



Fig. 10. Cyprella subannulata, Jones. Carboniferous, Ireland. 10a, Right 

 valve. 10 6, Ventral edge. Magnified B diam. 



Fig. 11. Entomoconchus Scouleri, McCoy. Carboniferous, Yorkshire. Right 

 valve. Magnified 3 diam. 



Fig. 12. Entomis divisa, Jones. Upper Silurian, from near Builth, South 

 Wales. The two valves exposed. Magnified 3 diam. 



Fig. 13. Entomis biconcentrica, Jones. Carboniferous, Ireland. 13 a, Left 

 valve. 13 6, Ventral edge. Magnified 3 diam. 



Fig. 14. Primltia renulina, Jones & Holl. Wenlock limestone. 14 a, Right 

 valve. 14 6, Dorsal view. Magnified 15 diam. 



Fig. 15. Kirkbya Urei, Jones. Carboniferous, Scotland. 15 «, Side view. 

 15 6, Ventral view. Magnified 5 diam. 



Fig. 16. Moorea silurica, Jones & Holl. Upper Ludlow, Malvern. 16 a, Left 

 valve. 16 6, Ventral edge. Magnified 15 diam. 



Fig. 17. Leperditia Balthica, Hisinger. Upper Silurian, Gothland. 17 «, Per- 

 fect carapace, left valve seen. 17 6, Dorsal view. 17 c, Front end. 

 Magnified 2 diam. 



Fig. 18. Isochilina gracilis, Jones. Lower Silurian of Isle Jesus, Canada. 

 18 a, Right valve. 186, Ventral edge. 18c, End view. Magnified 

 5 diam. 



Fig. 19. Beyrichia Wilckenziana, Jones. Upper Silurian of Gothland. Right 

 valve. Magnified 5 diam. 



Fig. 20. Beyrichia Kloedeni, McCoy. Upper Silurian, Shropshire. Right 



valve. Magnified 5 diam. 

 Fig. 21. Beyrichia complicata, Salter. Caradoc and Bala Works, Wales. 



Right valve. Magnified 5 diam. 



Fig. 22. Leaia Leidyi, Lea. Coal Measures, South Wales. Right valve. 

 Magnified 5 diam. 



Fig. 23. Estheria membranacea, Pacht. Devonian, Livonia. Left valve. 

 Magnified 5 diam. 



Fig. 24. Estheria tenella, Jordan. Carboniferous, Lanarkshire. Right valve. 

 Magnified 5 diam. 



Note. — The figures given on this plate are copied after those of Professor 

 T. Rupert Jones's article "On Ancient Water-fleas of the Ostracodous and 

 Phyllopodous Tril)es [Bivalved Entomostraca. ]" (Monthly Microscopical 

 Jour., October, 1870, p 184, plate Ixi.) 



