PLATE 20
FIGURE 1-3. Nalica (Natica?) bolus Brown and Pilsbry (p. 84).
 1, 2. Height 14.5 mm, diameter 15.2 mm. Locality 159. Middle part of Gatun formation. USNM 561338.
 3. Height 9.7 mm, diameter 10.2 mm. Locality 175. Upper part of Gatun formation, eastern area. USNM
 561339.
 4-6. Natica (Naticarius) stenopa Woodring, n. sp. (p. 85).
 Upper part of Gatun formation, eastern area.
 4, 5. Type. Height 15.2 mmt, diameter 14.8 mm. Locality 177b. USNM 561340.
 6. Paratype. Height 12 nmm, diameter 11 mn. Locality 177c. USNM 561341.
 7, S. Polinices canalizonalis (Brown and Pilsbry) (p. 89).
 Locality 177b. Upper part of Gatun formation, eastern area. USNM 561349.
 7. Height 21 mim, diameter 18.7 mm.
 8. Height 11 mm, diameter 10 mm.
 9. Potinices brunneus subclausus (Sonerby) (p. 89).
 Height 20.3 mm, diameter 16.7 mm. Locality 155 Middle part of Gatun formation. USNM 561350.
 10. Turbo (Marmarostonia) aff. T. castaneus Gmselin (p. 64).
 Height (not quite complete) 20.5 mn, diameter (incomplete) 18 mn. Locality 155b. Middle part of Gatun formation. USNM 561326.
 11-16. Stigiaulax fuppiana (Toula) (p. 86).
 11, 12. Height 22.5 mm, diameter 20.8 mi. Locality 155c. Middle part of Gatun formation. USNM1 561344.
 13. Length 18.5 mm, width 10.7 mtt. Locality 147g. Middle part of Gatun formation. USNM 561345.
 14. Length 17.5 mm, width 10 mn. Locality 147h. Middle part of Gatun formation. USNM 561446.
 15. Length 19.5 mn, width 10.9 min. Locality 151. Middle part of Gatun formation. USNAs 561347.
 16. Height 33.5 mm, diameter 30.5 mt. Locality 147b. Middle part of Gatun formation. USNAI 561342.
 17. Height 30.5 mm, diameter 29 it1M. Locality 177b. Upper part of Gatun formation, eastern area. USNM
 561343.
 18. Height 31.4 mm, diameter 28 mmn. Locality 142. Middle part of Gatun formation. USNM 561428.