Bull. U S. F. C. 1893. Pearls and Pearl Shells. 



Plate 33. 



PEARLY KNOB, MHeagrina margaritifera. Six by five and a half inches Thursday Island, Tahiti, 



MOTHER-OF-PEARL SHELL WITH PEARLY KNOB WITH MONKEY-LIKE FACE 



Four and a half by four and a half inches. Thursday Island, Tahiti. 



