EXPLANATION OF PLATES. 347 



PLATE 55. 



1. Onithochiton lyellii Sowb. Conch. Illustr., . . . 247 



2. Onithochiton lyellii Sowb. Conch. Icon., . . . 247 

 3-7. Onithochiton lyellii Sowb. Emerton del., . . . 247 

 8, 9. Onithochiton incii Kv. (=lyellii Sowb.). Conch. Icon., 248 



10, 11. Onithochiton semisculptus Pils. Ross del., . .247 



12, 13. Onithochiton quercinus Old. U. S. Exped., . . 248 



14, 15. Onithochiton undulatus Q. & G. Ross del., . . 245 



16. Onithochiton undulatus Q. & G. Voy. Astrol., . . 245 



17, 18. Plaxiphora wahlbergi Kr. Siidaf. Moll., . . .322 



19. Onithochiton rugulosus Ang. P. Z. S., . . . . 249 



20. Onithochiton maillardi Desh. Moll. Reun., . . .250 

 21-23. Onithochiton literatus Kr. Siidafrik. Moll., . . 251 



PLATE 56. 



1, 4, 6. Pallochiton lanuginosus Cpr. Ross del., . . 257 



2, 3. Pallochiton lanuginosus Cpr. Pilsbry del., . . 257 

 5, 7-11. Pallochiton lanuginosus Cpr. Emerton del., . . 257 



12-16. Nuttallina californica Nutt. Emerton del., . . 279 

 17, 18. Nuttallina californica Nutt. Ross del., . . .279 

 19, 20. Nuttallina scabra Rve. Ross del., . . . .280 



PLATE 57. 



21. Dinoplax gigas Gmel. Conch. Icon., .... 255 



22. 27-31. Dinoplax gigas Gmel. Emerton del:, . . . 255 

 23-26. Dinoplax gigas Gmel. (young). Siidafrik. Moll., . 255 



32. Dinoplax gigas Gmel. (young). Ross del., . . . 255 



33. 35. Tonicia confossa Gld. Pilsbry del., . . . .210 



34. Tonicia confossa Gld. U. S. Expl. Exped., . . . 210 



PLATE 58. 



1, 2. Callistochiton crassicostatus Pils. Emerton del., . .264 

 3-6. Callistochiton crassicostatus Pils. Pilsbry del., . . 264 

 Fig. below 1, and 7, 8. Callistochiton palmulatus Cpr. Emerton 



del., 262 



9-11. Callistochiton palmulatus var. mirabilis Pils. Pilsbry 



del., 263 



12. Callistochiton palmulatus (typical). Pilsbry del., . . 262 

 13-16. Callistochiton palmulatus (typical). Emerton del., . 262 

 17. Callistochiton decoratus Cpr. Ross del., . . . 269 



18-20. Callistochiton decoratus Cpr. Pilsbry del., . . 269 

 21, 22. Plaxiphora c^elata Rve. Conch. Icon., . . .328 



PLATE 59 



21-26. Callistochiton pulchrior Cpr. (=pulchellus Gray). 



Foord del., 272 



