Mournal, Ose tate | Ostracodous and Phyllopodous Tribes. 185 
sistency of certain generic types (judging from the remaining cara- 
pace-valves), and as to the coexistence in the early forms of several 
EXPLANATION OF PLATE LXI. 
[The small horizontal lines indicate the length of the valves when magnified 
Fig. 
1, 
two diameters, for comparison with Figs. 17 a—c.] 
Bairdia curta, M‘Coy. Mountain-limestone; Carboniferous. From the 
original specimen, free of the matrix. la. Left valve seen. 1. Ventral 
edge of the same valve. Magnified 15 diam. 
. Thlipsura corpulenta, Jones and Holl. Woolhope beds; Upper Silurian. 
2a. Right valve seen. 20. Ventral aspect. 2c. Posterior extremity. 
Magnified 15 diam. 
. Cythere Jukesiana, Jones and Holl. Kildare limestone; Lower Silurian. 
3a. Right valve seen. 36, Ventral view. Magnified 15 diam. 
. Cytherella brevis, nov. Carboniferous beds, six feet above the Eurypterus- 
limestone; Carluke, Scotland. Magnified 15 diam. 
. Cytherellina siliqua, Jones. Upper Silurian. 5a, Internal cast, with 
part of the shell, showing level outside and undulated interior. 50. 
Right valve. 5c. Edge view. 5d. End view. Magnified 15 diam. 
. Aichmina cuspidata, Jones and Holl. Wenlock limestone; Upper Silurian. 
Right valve. Magnified 15 diam. 
. Carbonia Agnes, Jones. Coal-measures; South Wales. 7a. Left valve. 
7b. The internal cast of the muscle-spot and its neighbourhood, in the 
variety rugulosa. Magnified 70 diam. 7c. The external aspect of the 
muscle-spot in C, Agnes. Magnified 70 diam. 
. Cypridina Phillipsiana, noy. Mountain-limestone; Ireland. 8a. Right 
valve. 80. Ventral edge. Magnified 3 diam. 
. Cypridella Koninckiana, nov. Mountain-limestone; Ireland. 9a, Right 
valve. 95, Ventral edge. Magnified 3 diam. 
. Cyprella subannulata, noy. Mountain-limestone; Ireland. 10a. Right 
valve. 10. Ventral edge. Magnified 3 diam. 
. Entomoconchus Scouleri, M‘Coy. Mountain-limestone; Yorkshire. Right 
valve in view. Magnified 3 diam. 
. Entomis divisa, Jones. Upper Silurian; from near Builth, South Wales. 
The two valves exposed. Magnified 3 diam. 
. Entomis biconcentrica, noy. Mountain-limestone; Ireland. 13a. Left 
valve. 136. Ventral edge. Magnified 3 diam. 
. Primitia renulina, Jones and Holl. Wenlock limestone. 14a. Right 
valve seen. 144. Dorsal view. Magnified 15 diam. 
. Kirkbya Urei, Jones. Carboniferous; Scotland. 15a. Side view. 150. 
Ventral view. Magnified 5 diam. 
. Moorea silurica, Jones and Holl. Upper Ludlow rocks; Malvern. 16a. 
Left valve. 166. Ventral edge. Magnified 15 diam. 
. Leperditia Balthica, Hisinger, sp. Upper Silurian; Gothland. 17a. Per- 
fect carapace, left valve seen. 170. Dorsal view. 17c. Front end. 
Magnified 2 diam. 
. Isochilina gracilis, Jones. Lower Silurian of Isle Jesus, Canada. 18a. 
Right valve. 186. Ventral edge. 18c. End view. Magnified 5 diam. 
. Beyrichia Wilckenziana, Jones. Upper Silurian of Gothland. Right valve. 
Magnified 5 diam. 
. Beyrichia Kloedeni, M‘Coy. Upper Silurian; Shropshire. Right valve. 
Magnified 5 diam. 
. Beyrichia complicata, Salter. Caradoc and Bala works; Wales. Right 
valve. Magnified 5 diam. 
. Leaia Leidyi, Lea, sp. Coal-measures; South Wales. Right valve. 
Magnified 5 diam. 
. Estheria membranacea, Pacht, sp. Devonian; Livonia. Left valve. 
Magnified 5 diam. 
. Estheria tenella, Jordan, sp. Carboniferous; Lanarkshire. Right valve. 
Magnified 5 diam. 
