282 Bulletin 39 454 



Page 



4. Crassatellites Reevei Gabb, Banana River, slightly reduced.. 212 



5. Spondylus chiriquiensis, n. sp., Water Cay, young right 



valve 206 



6. Spondylus chiriquiensis, n. sp. , Water Cay, young left valve. 



PLATE 21 (24) 



Fig. 1. Spondylus gumanomocon Brown and Pilsbry, Hone Walk 



Creek, shell greatly reduced 207 



2. Ostrea costaricensis, n. sp., Rio Blanco, about natural size... 196 



3. Placunanomia lithobleta Dall, Banana River, height 36 mm.. 210 



4. Placunanomia lithobleta Dall, Banana River, height 49 mm 



5. Placunanomia lithobleta Dall, interior of same specimen as 



figure 3. 



6. Anomia simplex d'Orbigny, Middle Creek, height 34 mm 209 



7. Corbula gatunensis Toula, Gatun, length 21 mm. 



S. Corbula Dietziana C. B. Adams, Port Limon, length 15.5 mm. 268 

 9. Corbula orosi, n. sp., type. Banana River, length 19.5 mm ... 269 



10. Corbula orosi, n. sp., type, Binana River, length T9 mm. 



11. Labiosa lineata Say, Saury Creek, length 44 mm 264 



12. Corbula hexacyma Brown and Pilsbry, Gatun, length 26 mm. 269 



13. Corbula hexacyma Brown and Pilsbry, Gatun, length 18 mm. 



PLATE 22 (25) 



Fig. I. Area occidentalis Phil., Port Limon, somewhat enlarged 181 



2. Area umbonata Lamarck, East Grape Point Creek, slightly 



enlarged 182 



3. Area auriculata Lamarck,, Old Man Sam Creek, young shell.. 190 



4. Area Mauryae, n. sp., Port Limon, right valve of type , length 



24 mm 182 



5. Area Candida Gmelin, Port Limon, left valve, length 18 mm. 183 



6. Area Candida Gmelin, Port Limon, right valve length 



13 mm. 



7. Area Mauryae, n. sp. , interior view of type 182 



8. Area honensis, n. sp., Hone Walk Creek, left valve type, 



slightly reduced 187 



9. Area honensis, n. sp, , same locality, right valve of cotype, 



slightly reduced 187 



10. Area dariensis Brown and Pilsbry, Water Cay, about natural 



size 184 



