2 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 79 : art. 12 



Remarks. — The United States National Museum contains other 

 specimens from the Pearl and Hermes reefs, as well as from the 

 islands of Maui, Oahu, and Hawaii. 



The short hinge and deeply folded byssal notch suggest a de- 

 cided relationship with Pinctada margaHtifera (Linnaeus). This 

 becomes emphasized in young shells, which have the dark marginal 

 border characteristic of the dark-lipped shells. The yellow edge of 

 adult shells, on the other hand, suggests Pinctada maxima (Jame- 

 son), from which it may be at once distinguished by the short and 

 more oblique hinge. Some young specimens of the present species 

 suggest Pinctada margaHtifera cumingi (Reeve). This, however, is 

 a much smaller species with decidedly darker inner border; it also 

 has a much more strongly rayed exterior, and comes from Lord 

 Hood Island, situated on the Paumotu shelf, which is quite distinct 

 from the platform of the Hawaiian group. 



I have attempted to show some of these differences in the plates. 



EXPLANATION OF PLATES 1 AND 2 



Figures 1, 2. 3. Pinctada galtnoffi, new species. 



4, 5. Pinctada margaHtifera cumingi (Reeve) from Raiatea Island, 

 Society Islands. 

 6. Pinctada maxima (Jameson) from Bubuau Island, Jolo, 

 Philippine Islands. 

 7, 8. Pinctada galtsoffi, new species. Type specimen. 



U, S. SOVSRMMEKT PSINTIdS Of 



