Plate V1ii. 
Page 
Fig. 1.:-Ctenobolbina ‘ciliata, (Emmons). ...>- 3. ee 108 
1a, left valve of average specimen, x 18; 14, interior of right valve, 
x 18. 
Fig. 2. Ctenobolbina cihata, var: curta, 1. var. 52 2 ee 109 
Left valve, x 18. 
Fig. 3. Ctenobolbina ciliata, var. emaciata, n: vars. eee 109 
3a, left valve, x 20; 30, posterior view of same; 3c, ventral view 
of same. 
Fig: 4. Ctenobolbina alata, n. sp. :.°.25..  : 2 TIO 
4a, left side of small example, x 18; 44 and 4c, ventral and dorsal 
views of two larger specimens, x 25. 
Fig. 5. Ctenobolbina tumida, n. sp..-2 2)... = III 
5a, left valve, x 18, with the anterior ridge less sharply elevated 
than usual; 54, dorsal view of same in outline. 
lig. 6. Ctenobolbina bispinosa, n- sp... 2) 3 eee IIO 
Rather small, perfect right valve, x 18. 
Fig. 7. Primitia perminima, n.sp.....). 22.2) 131 
Right valve, x 18. . 
Fig. 8. Jonesella crepidiformis, Ulrich..... Sle ir 122 
a right side of an average example of this species, x 18; 84 and 
8c, ventral and posterior views of same. 
Hig, 9: Jonesella pedigera, n. Sp... 2... 2 122 
ga, left valve, x 18; 9a, posterior view of same. 
Fig..10; Jonesella digitata, n. sp... 6..." °. 26) rr 122 
loa, right valve, x 20; 106 and 10c, dorsal and posterior views of 
same. 
Fig. 11. Jonesella-crassa, ny Sp >.77..2 2. L232 
11a left valve, x 20; 114, dorsal view of same. 
Fig. 12; -Entomis madisonensis; n- sp..... 2.52 eee 107 
12a, left valve, x 18; 120, ventral view of same. 
